Glial Cell Line-Derived Neurotrophic Factor and Somatostatin Levels in Cerebrospinal Fluid of Patients Affected by Chronic Migraine and Fibromyalgia

The aim of the present study was to verify cerebrospinal fluid (CSF) levels of glial cell line-derived neurotrophic factor (GDNF) and somatostatin, both measured by sensitive immunoassay, in: 16 chronic migraine (CM) patients, 15 patients with an antecedent history of migraine without aura diagnosed as having probable chronic migraine (PCM) and probable analgesic-abuse headache (PAAH), 20 patients affected by primary fibromyalgia syndrome (PFMS), and 20 control subjects. Significantly lower levels of GDNF and somatostatin were found in the CSF of both CM and PCM + PAAH patients compared with controls (GDNF = P < 0.001, P < 0.002; somatostatin = P < 0.002, P < 0.0003), without significant difference between the two groups. PFMS patients, with and without analgesic abuse, also had significantly lower levels of both somatostatin and GDNF ( P < 0.0002, P < 0.001), which did not differ from those of CM and PCM + PAAH patients. A significant positive correlation emerged between CSF values of GDNF and those of somatostatin in CM ( r = 0.70, P < 0.02), PCM + PAAH ( r = 0.78, P < 0.004), and PFMS patients ( r = 0.68, P < 0.008). Based on experimental findings, it can be postulated that reduced CSF levels of GDNF and somatostatin in both CM and PCM + PAAH patients can contribute to sustained central sensitization underlying chronic head pain. The abuse of simple or combination analgesics does not seem to influence the biochemical changes investigated, which appear to be more strictly related to the chronic pain state, as demonstrated also for fibromyalgia.

Negative correlation between neuropeptide Y profile in the cerebrospinal fluid and growth hormone pulses in the peripheral circulation in goats

BACKGROUND/AIMS

Growth hormone (GH) is secreted in pulsatile fashion, but the involvement of neuropeptides in the generation of GH pulses is not fully understood. The present study was conducted to elucidate the relationship between GH pulses and neuropeptide levels in the cerebrospinal fluid (CSF) of the third ventricle in ovariectomized goats.

METHODS

CSF and plasma samples were collected every 15 min. Levels of plasma GH and profiles of GH-releasing hormone (GHRH), somatostatin (SRIH) and neuropeptide Y (NPY) in the CSF were measured by radioimmunoassay. Pulse/trough characteristics and correlations were assessed by the ULTRA algorithm, cross-correlation analysis and approximate entropy test.

RESULTS

The periodicity of GH pulses was 2.20 h. Although most GH pulses were associated with GHRH peaks, there was no correlation between GH and GHRH or GH and SRIH. NPY levels in the CSF fluctuated episodically at 2.03-hour intervals. GH pulse peaks occurred 0-30 min after NPY troughs, and there was a significant negative cross-correlation and negative synchronicity between GH and NPY profiles. In addition, intracerobroventricular infusion of NPY suppressed GH secretagogue (KP102)-induced GH release.

CONCLUSION

The periodic decrease in NPY may be involved in the generation of GH pulsatility in goats.

Discrimination of Alzheimer patients responding to cholinesterase inhibitor therapy

We have studied whether it is possible to discriminate responders to tacrine treatment from patients nonresponsive to tacrine in Alzheimer's disease. The results indicate that mildly demented patients will most likely gain a benefit of tacrine treatment. Neuropsychological tests on attention and working memory after a single dose of tacrine might be useful as well as a single dose pharmaco-EEG in discriminating responders to treatment.

Somatostatin and Alzheimer's disease

Alzheimer's disease (AD) is characterized by the cerebral deposition of senile plaques that are mainly composed of a set of peptides referred to as amyloid beta-peptides (Abeta). Among the numerous neuropeptides produced in intrinsic cortical and hippocampal neurons, somatostatin (SRIF) has been found to be the most consistently reduced in the brain and cerebrospinal fluid of AD patients. SRIF receptors (SSTR), which mediate the neuromodulatory signals of SRIF, are also markedly depleted in the AD brain, there being subtype-selective alterations in cortical areas. In the rat temporal cortex, we have shown that intracerebroventricular infusion of Abeta25-35 results in a decrease in SRIF-like immunoreactivity and in SRIF receptor subtype 2 (SSTR2) mRNA and protein levels, in correlation with a decrease in SSTR functionality. Insulin-like growth factor-I prevents the reduction in these parameters induced by Abeta25-35. Abeta has recently been demonstrated to be degraded primarily by a neutral endopeptidase, neprilysin, in the brain. SRIF regulates brain Abeta levels via modulation of neprilysin activity. Because SRIF expression in the brain declines upon aging in various mammals, including rodents, apes and humans, the aging-dependent reduction of SRIF has been hypothesized to trigger accumulation of Abeta in the brain by suppressing neprilysin action. Here we present an overview of recent advances on the role of SRIF in AD and its relationship with Abeta peptides.

Relationship between growth hormone (GH) pulses in the peripheral circulation and GH-releasing hormone and somatostatin profiles in the cerebrospinal fluid of goats

Growth hormone (GH) is secreted in a pulsatile manner, but the underlying mechanisms of GH pulse generation remain to be resolved. In the present study, we investigated the relationship between GH pulses in the peripheral circulation and GH-releasing hormone (GHRH) and somatostatin (SRIF) profiles in the cerebrospinal fluid (CSF) of male goats. The effects of an intracerebroventricular (icv) injection of neuropeptide Y (NPY), galanin and ghrelin were also analyzed. Blood and CSF samples were collected every 15 min for 8 hr from the jugular vein and third ventricle, respectively. GH pulsatility in the goat was found to consist of distinct large pulses of 5 hr periodicity and small pulses of 1 hr periodicity. GHRH and SRIF in the CSF fluctuated in a pulsatile manner with 1 hr periodicity, and most of the descending phase of SRIF pulses were associated with the initiation of GH pulses. Icv injections of NPY, galanin and ghrelin stimulated GHRH release without affecting SRIF release. In addition, NPY suppressed, and galanin and ghrelin induced large GH pulses, although ghrelin was much more effective than galanin. These results suggest that an hourly fall in SRIF is involved in generating intrinsic circhoral rhythm of GH pulsatility. The mechanisms underlying the generation of large GH pulses of 5 hr periodicity remain unknown, while direct action of NPY and/or ghrelin on the pituitary might be involved.

Corticotropin-releasing factor in posttraumatic stress disorder (PTSD) with secondary psychotic symptoms, nonpsychotic PTSD, and healthy control subjects

BACKGROUND

Recent studies have reported a high comorbidity between posttraumatic stress disorder (PTSD) and psychotic symptoms, and it has been hypothesized that PTSD with comorbid psychosis is a severe form of PTSD. Few studies have examined the neurobiology of PTSD with comorbid psychosis. If PTSD with secondary psychotic symptoms (PTSD-SP) is a severe form of PTSD, then it might be expected to show more extreme perturbations in the neuroendocrine patterns that characterize PTSD.

METHODS

Patients with PTSD with secondary psychotic symptoms (PTSD-SP), PTSD without psychosis, and healthy comparison subjects were compared for differences in cerebrospinal fluid concentrations of corticotropin-releasing factor (CRF) and somatotropin-release-inhibiting hormone (SRIF).

RESULTS

The PTSD-SP subjects had significantly higher mean levels of CRF than either the PTSD or control subjects (p <.01). The three groups showed similar SRIF levels.

CONCLUSIONS

These data implicate abnormalities in the secretion of CRF with the production of secondary psychotic symptoms in PTSD. This finding supports the validity of PTSD-SP as a PTSD subtype and as a severe form of PTSD.

Correlation between spontaneous feeding behavior and neuropeptide Y profile in the third ventricular cerebrospinal fluid of goats

Feeding behavior is regulated by neural signals in the hypothalamus, but secretory activities of these signals in vivo and their relationship with spontaneous feeding remain to be solved. In the present study, we investigated the correlation between neuropeptide Y (NPY) and somatostatin (SRIF) profiles in cerebrospinal fluid (CSF) and spontaneous feeding behavior in goats. CSF samples were collected every 15 min for 8 h from the third ventricle and feeding behavior was observed throughout the experimental period. The spontaneous feeding behavior, the mean duration of which was 58 min, occurred with an interval of 146 min. NPY in the CSF fluctuated in an episodic fashion with a 145 min interval. Each NPY episode was followed by spontaneous feeding with a time lag of 24 min. SRIF levels in CSF changed more frequently in a pulsatile manner and were related to neither NPY profiles nor feeding behavior. These results suggest that NPY, but not SRIF, is a physiological signal to drive feeding in goats.

Low CSF somatostatin associated with response to nimodipine in patents with affective illness

BACKGROUND

In patients with depression, treatment with nimodipine has been shown to increase cerebrospinal fluid (CSF) somatostatin (SRIF) and ameliorate baseline global cerebral hypometabolism. This study was conducted to assess whether a low baseline level of CSF SRIF was associated with response to nimodipine treatment.

METHODS

Twenty-one depressed patients underwent lumbar puncture for analysis of CSF somatostatin-like immunoreactivity (SRIF-LI) during a medication-free period and after at least 6 weeks of nimodipine monotherapy. Twenty-five healthy control subjects were utilized as a comparison group. Clinical improvement was assessed using the Clinical Global Impression Scale for Bipolar Illness.

RESULTS

As predicted, baseline CSF SRIF-LI was significantly lower in eventual nimodipine responders (33.1 +/- 2.8 pg/mol) compared to eventual nonresponders [41.9 +/- 2.6 pg/mL; t(19) = 1.98, p =.03, one-tailed].

CONCLUSIONS

Low baseline CSF somatostatin in depression may be associated with response to nimodipine, which in turn may be related to the ability of nimodipine to increase CSF somatostatin.

Alzheimer disease - effect of continuous intracerebroventricular treatment with GM1 ganglioside and a systematic activation programme

Five patients with the early-onset form of Alzheimer disease (AD) received GM1 ganglioside by continuous injection into the frontal horns of the lateral ventricles for a period of 12 months. The optimal GM1 dose varied between 20 and 30 mg/24 h. The patients were trained twice a week for 4-5 h with an individually designed cognitive programme, which included the use of a word processor. Neurological, neuropsychological, psychiatric and neurochemical examinations were performed a week before surgery and on days 30, 90, 180, 270 and 365 after surgery. The cerebrospinal fluid levels of the monoamine metabolites homovanillic acid and 5-hydroxyindoleacetic acid and the neuropeptide somatostatin increased. The regional cerebral blood flow showed a tendency to increase. The progression of deterioration was stopped, and motor performance and neuropsychological assessments improved. The patients became more active and felt safer in relation to other people and performing various activities. They had improved reading comprehension and a better feeling for language. They were able to write reports and short letters on a word processor. When interviewed at the end of the study, all 5 patients stated that they felt better, and their relatives reported that they had regained integrity and their joie de vivre.

Processing of neuropeptide Y, galanin, and somatostatin in the cerebrospinal fluid of patients with Alzheimer's disease and frontotemporal dementia

Alzheimer's disease (AD) and frontotemporal dementia (FTD) are two prevalent neurodegenerative disorders for which the causes are unknown, except in rare familial cases. Several changes in neuropeptide levels as measured by radioimmunoassay (RIA) have been observed in these illnesses. Somatostatin (SOM) levels in cerebrospinal fluid (CSF) are consistently decreased in AD and FTD. Neuropeptide Y (NPY) levels are decreased in AD, but normal in FTD. Galanin (GAL) levels increase with the duration of illness in AD patients. The majority of studies of neuropeptides in CSF have not been verified by HPLC. The observed decrease in a neuropeptide level as measured by RIA may therefore reflect an altered synthesis or extracellular processing, resulting in neuropeptide fragments that may or may not be detected by RIA. Matrix-assisted laser desorption time-of-flight mass spectrometry (MALDI-MS) has been shown to be a powerful technique in the analysis of biological materials without any pre-treatment, by detecting peptides and proteins at a specific mass-to-charge (m/z) ratio. We studied the processing of the neuropeptides NPY, NPY, SOM and GAL in the cerebrospinal fluid of patients with AD (n = 3), FTD (n = 3) and controls (n = 2) using MALDI-MS. We found that considerable inter-individual variability exists in the rate of neuropeptide metabolism in CSF, as well as the number of peptide fragments formed. Certain patients showed differences in the processing of specific neuropeptides, relative to other patients and controls. This analysis of the metabolic processing of neuropeptides in CSF yielded a large amount of data for each individual studied. Further studies are required to determine the changes in neuropeptide processing that can be associated with AD and FTD. With further investigations using MALDI-MS analysis, it may be possible to identify a neuropeptide fragment or processing enzyme that can be correlated to these disease states.

A follow up study of suicide attempters: increase of CSF-somatostatin but no change in CSF-CRH

Concentrations of somatostatin and corticotrophin releasing hormone (CRH), measured in cerebrospinal fluid (CSF) have been reported to be low in suicidal patients with major depressive disorder (MDD). Often have MDD patients in general, high CSF-CRH and low CSF-somatostatin concentrations, which both seem to normalise with clinical recovery. The present study was designed to look for CSF-CRH and CSF-somatostatin alterations along with clinical changes in patients studied repeatedly after a suicide attempt. Sixteen patients with different diagnoses, initially inpatients after a suicide attempt (baseline), participated. Lumbar punctures and ratings according to the Suicidal Assessment Scale (SUAS) and the Montgomery-Asberg Depression Rating Scale (MADRS) were performed while patients were drug-free (baseline) and after a median of 7 (5 to 9) months. At follow up MADRS- and SUAS-scores were significantly decreased (P<0.05), whereas CSF-somatostatin was significantly increased (P=0.013) and CSF-CRH had not changed significantly. Thus, the patients showed long-lasting low CSF-CRH concentrations, in spite of changed CSF-somatostatin concentrations and clinical amelioration.

Shunt related changes in somatostatin, neuropeptide Y, and corticotropin releasing factor concentrations in patients with normal pressure hydrocephalus

OBJECTIVES

Recent data indicate that alterations in brain neuropeptides may play a pathogenic role in dementia. Neuropeptide Y (NPY), somastostatin (SOM), and corticotropin releasing factor (CRF) are neuropeptides involved in cognitive performance. Decreased SOM and NPY concentrations have been found in patients with normal pressure hydrocephalus and are probably the result of neuronal dysfunction, which could potentially be restored by shunting. The effects of shunt surgery on preoperative SOM, NPY, and CRF concentrations were studied. Any improvements in neuropeptide concentrations that could lead to clinically significant neuropsychological and functional changes were also investigated.

METHODS

A prospective study was performed in 14 patients with normal pressure hydrocephalus syndrome with a duration of symptoms between 3 months and 12 years. Diagnosis was based on intracranial pressure (ICP) monitoring and CSF dynamics. Concentrations of SOM, NPY, and CRF in lumbar CSF were determined before shunting and again 6-9 months after surgery. A battery of neuropsychological tests and several rating functional scales were also given to patients before and after shunting.

RESULTS

After shunting, SOM and CRF concentrations were significantly increased in all patients. Concentrations of NPY were increased in 12 of the 14 patients studied. The clinical condition of 13 of the 14 patients was significantly improved 6 months after surgery. This improvement was more pronounced in gait disturbances and sphincter dysfunction than in cognitive impairment. No significant differences in any of the neuropsychological tests were seen for the group of patients as a whole despite the increased neuropeptide concentrations.

CONCLUSIONS

Shunting can restore SOM, NPY, and CRF concentrations even in patients with longstanding normal pressure hydrocephalus. However, despite the biochemical and clinical improvement in some areas such as ambulation and daily life activities, cognitive performance did not significantly improve. The role of neuropeptides in the diagnosis and treatment of patients with normal pressure hydrocephalus syndrome is discussed.

Cerebrospinal fluid concentrations of corticotropin-releasing hormone, vasopressin, and somatostatin in depressed patients and healthy controls: response to amitriptyline treatment

The effect of amitriptyline upon hypothalamic-pituitary-adrenal [HPA]-system-regulating neuropeptides (corticotropin-releasing hormone [CRH], vasopressin, somatostatin) was studied in a group of depressed elderly patients and controls. A first lumbar puncture was performed in 37 depressed in-patients. This was followed by a 6-week medication phase with amitriptyline. Upon its completion a second cerebrospinal fluid (CSF) sample was obtained in 18 of these 37 patients. In 25 healthy controls a first lumbar puncture was done eleven of these individuals agreed to take 75 mg/d amitriptyline for 6 weeks and to participate in the follow-up CSF study. Within the group of depressed patients amitriptyline led to a significant decrease of CSF CRH in treatment responders only (F1, 16 = 5.2; P < 0.02). Also, in normal controls CSF CRH concentration tended to decrease with amitriptyline treatment (t-test; P < 0.09). No effects of amitriptyline upon vasopressin or somatostatin were observed. In normal controls (r = 0.4; P < 0.02) and in patients (r = 0.4; P < 0.03) age correlated positively with baseline CSF somatostatin. A trend for CSF CRH to increase with aging was found only in controls (r = 0.3; P < 0.09); patients did not show a significant association here. Finally, CSF neuropeptide concentration at baseline did not differ between the group of depressed patients and healthy controls. Our study corroborates the evolving concept that antidepressants effect various components of the HPA system with the net result of a reduction in its activity. In addition, we found CSF CRH and CSF somatostatin concentrations to be better reflections of age than of depression and, finally, that during aging and during depression the HPA system changes in similar directions.

Cerebrospinal fluid somatostatin levels in febrile seizures and epilepsy in children

We analysed the level of cerebrospinal fluid (CSF) somatostatin in children with febrile seizures and epilepsy. In the febrile seizure group (n = 23), the somatostatin level was 83.9 +/- 11.2 pg/ml, which was significantly higher than that of age-matched controls. CSF samples obtained within 3 h of the last seizure had higher somatostatin levels (106.1 +/- 12.4 pg/ml;n = 14) than did the CSF obtained after 3 h (49.4 +/- 15.6 pg/ml;n = 9). The mean somatostatin level in the epilepsy group was 35.3 +/- 4.3 pg/ml (n = 34), and was distributed as follows: 27.6 +/- 3.6 pg/ml in the idiopathic generalized epilepsy group (n = 16), 44.0 +/- 9.4 pg/ml in the symptomatic generalized epilepsy group (n = 13), and 37.2 +/- 10.1 pg/ml in the partial epilepsy group (n = 5). The levels in each group were significantly higher than those in age-matched controls. Somatostatin is a hypothalamic tetradecapeptide with excitatory effects on neurons in children with febrile seizures and epilepsy. The finding that patients with convulsive disease had elevated levels of CSF somatostatin suggests that somatostatin release is somehow related to seizure activity. It remains to be determined whether this is due to increased release from over-active excitatory neurons or leakage from damaged or anoxic neurons, secondary to seizure activity.

Neurochemistry and delirium

Acute confusional state or delirium is one of the most common organic brain syndromes especially in the elderly. It develops suddenly, within hours or days, and often during a period of hospitalization. In this paper we review the results of our studies on the neurochemistry of delirium.

Cerebrospinal fluid somatostatin, mood, and cognition in multiple sclerosis

BACKGROUND

Cerebrospinal fluid (CSF) somatostatin (SS) levels have been shown to be decreased in multiple sclerosis (MS) during relapse as well as in disorders characterized by depression or cognitive impairment. Since MS is often associated with depression and cognitive impairment, we examined both the effect of course of illness on CSF SS as well as the variance in SS attributable to associated features (e.g., depression or cognitive impairment).

METHODS

Fifteen patients with chronic progressive MS participating in a 2-year cyclosporine trial underwent lumbar punctures for CSF SS at baseline and at 12 and 24 months. Additionally, patients were evaluated by neuropsychological testing, and physical disability and mood ratings. Baseline CSF SS levels were also obtained in a group of control subjects (n = 10).

RESULTS

At baseline, CSF SS levels were lower in MS patients than control subjects (p < .001). Decreased CSF SS at 24 months was correlated with decreased cognitive performance on several measures and was best and significantly predicted by cognitive deterioration at 24 months.

CONCLUSIONS

Our data support those from previous studies that found lower levels of CSF SS in MS during relapse and suggest that changes in CSF SS are related to the process responsible for diminished cognitive function in MS.

Effects of electro-acupuncture on somatostatin and pancreatic polypeptide in ischemic cerebrovascular diseases

The levels of somatostatin (SS) in CSF and blood and pancreatic polypeptide (PP) in plasma were measured by radioimmunoassay in 64 patients with acute ischemic cerebrovascular diseases (ICVD), randomly divided into two groups: group 1 (n = 31, both electro-acupuncture and routine treatments given) and group 2 (n = 33, routine treatment) and 26 non-ICVD patients were used as controls. The points of electro-acupuncture were Quchi (LI 12), Waiguan (SJ 5) and Huantiao (GB 30) and Zusanli (St 36). After a course of treatment, the SS levels in plasma and CSF were significantly increased in the patients of group 1 with good result and their plasma PP level had no significant change. In the patients with poor result, however, the PP level was significantly decreased. The results suggested that electro-acupuncture might play an active role in alleviating the SS metabolic disturbance in CNS of ICVD patients.

Cerebrospinal fluid somatostatin in West syndrome: changes in response to combined treatment with high-dose pyridoxal phosphate and low-dose corticotropin

Eighteen children with West syndrome (5-11 months of age) were selected to receive an oral dose of pyridoxal phosphate, (20-50 mg/kg) for 14 d. Seizures disappeared in one patient. The remaining 17 patients were treated with 0.01 mg/kg synthesized corticotropin intramuscularly for 2 weeks as an additional therapy. Seizures disappeared in all 17 patients within a few days after initiation of the corticotropin. Levels of somatostatin in the cerebrospinal fluid were as follows: 61.0+/-10.7 pg/ml before therapy, 34.2+/-6.4 pg/ml during pyridoxal phosphate therapy, and 26.8+/-4.2 pg/ml after 2 weeks corticotropin therapy. Somatostatin levels in untreated patients were higher (p < 0.05) than those of age-matched controls (35.7+/-11.8 pg/ml) and decreased (p < 0.05) after pyridoxal phosphate treatment. Somatostatin is a hypothalamic tetradecapeptide with excitatory effects on neurons and pyridoxal phosphate might subclinically influence neuronal excitation.

Cerebrospinal fluid concentrations of somatostatin and biogenic amines in grown primates reared by mothers exposed to manipulated foraging conditions

BACKGROUND

In an earlier study, infant primates were nursed by mothers randomly assigned to variable foraging demand (VFD) or nonvariable foraging conditions (non-VFD). A group of grown VFD-reared subjects demonstrated elevations of cisternal cerebrospinal fluid (CSF) corticotropin-releasing factor concentrations and decreased CSF cortisol levels vs non-VFD counterparts. To further characterize neurobiological sequelae of disturbed early rearing, CSF concentrations of serotonin, dopamine, and norepinephrine metabolites (5-hydroxyindoleacetic acid, homovanillic acid, and 3-methoxy-4-hydroxyphenethyleneglycol [MHPG], respectively) and of somatostatin were determined.

METHODS

Second CSF taps were obtained from the previously studied cohort of 30 subjects and from 28 age-matched ad libitum-reared control subjects. Relevant assays were performed.

RESULTS

All neurochemicals assayed except MHPG were elevated in the VFD-reared compared with non-VFD subjects. In the VFD group, statistically significant positive correlations between corticotropin-releasing factor and each neurochemical was found, except for MHPG. In the non-VFD subjects, no significant correlations with corticotropin-releasing factor were observed. No effect of age was evident.

CONCLUSIONS

Reducing the predictability of maternal foraging demand during early rearing was associated with elevations of cisternal somatostatin and of serotonin and dopamine metabolite concentrations in grown offspring. The corticotropin-releasing factor elevations reported previously were positively correlated with all the elevated CSF parameters of the current study. The findings support the notion that adverse early rearing experiences in primates have longstanding and complex effects on a range of neurochemicals relevant to emotional regulation. Replication in prospective age-controlled studies is warranted.

[Frequency dependence of somatostatin and calcitonin gene related peptide release induced by electroacupuncture in rat spinal cord]

Radioimmunoassay (RIA) was used to determine the changes of the immunoreactivity (ir) of somatostatin (SOM) and calcitonin gene-related peptide (CGRP) in the spinal perfusate of rat induced by electroacupuncture (EA) of different frequencies. The frequency of EA was chosen to be 2, 15 and 100 Hz and the spinal perfusate was collected in three periods of 30 min before, during and after EA. The results indicate: (1) low frequency EA (2 Hz) increased the spinal SOM-ir level by 39% (P < 0.05) but decreased that of CGRP-ir by 47% (P < 0.05); (2) conversely, 15 Hz EA decreased spinal fluid SOM-ir level by 37% (P < 0.05) but increased that of CGRP-ir by 92% (P < 0.05); (3) 100 Hz EA behaved like 15 Hz in inhibiting SOM-ir level (P < 0.01), but without effect on CGRP-ir. The above results show that specific frequency is required for peripheral electrical stimulation to activate or suppress the release of spinal neuropeptides SOM and CGRP, a fact that may have clinical implications.

Processing of neuropeptide Y and somatostatin in human cerebrospinal fluid as monitored by radioimmunoassay and mass spectrometry

The processing of four neuropeptides, neuropeptide Y (NPY) 1-36, NPY (18-36), somatostatin (SOM) 1-28, and SOM (15-28) was studied in human cerebrospinal fluid (CSF) by using a novel combination of methods that included radioimmunoassay (RIA) and mass spectrometry. Untreated CSF samples were chromatographed using reversed-phase high pressure liquid chromatography (RP-HPLC) followed by NPY-RIA or SOM-RIA. These results were compared with those obtained by incubating CSF with exogenous synthetic peptides and directly detecting peptide fragments by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-MS). Using this combination of methods, we were able to determine the probable identities of peptides/peptide fragments recognized in radioimmunoassays. The most important NPY-immunoreactive components in CSF were found to be NPY (1-36) and NPY (3-36). Metabolic products of SOM (15-28) were found to contribute to SOM-like immunoreactivity (SOM-LI) in CSF, but SOM (1-28) only to a lesser degree. Differences in the rate of neuropeptide processing were observed. These differences depended more on the length of the peptide than its sequence. NPY (18-36) and SOM (15-28) were rapidly and extensively processed, whereas NPV (1-36) and SOM (1-28) were processed much more slowly in CSF. The production of SOM (15-28) from SOM (1-28) by enzymes in CSF was not observed. Also, the presence of a disulfide bond in the somatostatins appeared to stabilize them against enzymatic digestion of the ring structure. The results detailed in this report confirm MALDI-MS important role in studies of neuropeptide processing in CSF.

Somatostatin and neuropeptide Y in cerebrospinal fluid: correlations with severity of disease and clinical signs in Alzheimer's disease and frontotemporal dementia

Alzheimer's disease (AD) and frontotemporal dementia (FTD) are the most common types of progressive neurodegenerative disorder in our catchment area. The distribution of cortical degeneration in FTD is mainly the reverse of that in AD, while there are both differences and similarities in the clinical characteristics. Somatostatin and neuropeptide Y (NPY) are neuropeptides with a widespread distribution in the human cerebral cortex. Somatostatin is involved in the regulation of hormone release from the anterior pituitary and may act as a neurotransmitter-modulator. NPY is a potent anxiolytic neuropeptide. Somatostatin and NPY coexist in the cerebral cortex, basal ganglia and in amygdaloid complexes. The present study of AD (n = 34) and FTD (n = 22) analyses the cerebrospinal-fluid (CSF) levels of somatostatin-like immunoreactivity and NPY-like immunoreactivity and correlates their levels to 54 different clinical items, such as restlessness, anxiety, irritability and depression. The CSF levels of the two neuropeptides somatostatin and NPY were significantly correlated in FTD (p < 0.02), but not in AD. Several significant correlations to the clinical signs were found: in AD disorientation and dyspraxia, and in FTD agitation, irritability and restlessness. Somatostatin showed a significant negative correlation with severity of dementia in AD (p < 0.013).

Molecular forms of somatostatin-like immunoreactivity in the cerebrospinal fluid of patients with senile dementia of the Alzheimer type

In the cerebrospinal fluid (CSF) of 53 patients with senile dementia of the Alzheimer type (SDAT) and 12 elderly controls, we measured somatostatin (SLI) and its molecular forms: high-molecular weight form (HMV-SST), somatostatin-14 (SST-14), somatostatin-25/28 (SST-28/25), and des-ala-somatostatin (des-ala-SST) using high pressure liquid chromatography (HPLC) and a radioimmunoassay. In SDAT, SLI was significantly decreased (p < 0.05) and correlated with dementia scores (r = -0.65, p < 0.05). HPLC separation showed a marked heterogeneity of SLI in the CSF with a preponderance of SST-14 and SST-25/28. The significant loss of SST-14 (p < 0.05) in SDAT was found to be correlated with dementia scores (r = 0.65). Moreover, qualitative and quantitative changes in the molecular pattern of SLI in SDAT indicated dysregulated synthesis and/or processing of somatostatin relating to the severity of dementia. The long-term administration of neuroleptics in severe cases of SDAT caused a significant increase of SLI (p < 0.05) and influenced the ratio of HMV-SST/SST-14 and SST25/28/SST-14.

Elevated CSF corticotropin-releasing factor concentrations in posttraumatic stress disorder

OBJECTIVE

Corticotropin-releasing factor (CRF) and somatostatin both play important roles in mediating responses to acute and chronic stress. The purpose of this study was to measure CSF concentrations of CRF and somatostatin in patients with chronic combat-related post-traumatic stress disorder (PTSD) and comparison subjects.

METHOD

Lumbar punctures for collection of CSF were performed in Vietnam combat veterans with PTSD (N = 11) and comparison subjects (N = 17). CSF concentrations of CRF and somatostatin were compared between the two groups.

RESULTS

CSF concentrations of CRF were higher in the PTSD patients than in the comparison subjects (mean = 29.0 pg/ml, SD = 7.8, versus mean = 21.9 pg/ml, SD = 6.0). This group difference remained significant after covariance for age. CSF somatostatin concentrations in PTSD patients were higher than those of the comparison subjects (mean = 19.9 pg/ml, SD = 5.4, versus mean = 13.7 pg/ml, SD = 8.0). However, covarying for age reduced the level of significance.

CONCLUSIONS

Higher CSF CRF concentrations in patients with PTSD may reflect alterations in stress-related neurotransmitter systems. The higher CSF CRF concentrations may play a role in disturbances of arousal in patients with PTSD.

Cerebrospinal fluid neuropeptides and monoaminergic transmitters in patients with trigeminal neuralgia

The pathogenesis of trigeminal neuralgia remains largely unknown. "Peripheral" as well as "central" causes have been suggested. To investigate the role of serotonergic, noradrenergic, dopaminergic, and peptidergic systems, we determined the concentrations of epinephrine, norepinephrine, and their breakdown product, vanillylmandelic acid, in the cerebrospinal fluid of 16 patients (55.3 +/- 8.3 years) with trigeminal neuralgia. As a marker for the dopaminergic system, we determined cerebrospinal fluid concentrations of dopamine and its metabolite, homovanillic acid. As a marker for the serotonergic system, we measured cerebrospinal fluid levels of the serotonin metabolite, 5-hydroxyindoleacetic acid. In addition, levels of the neuropeptides, substance P and somatostatin, were determined. The concentration of norepinephrine (P < 0.01) and its metabolite, vanillylmandelic acid, (P < 0.05) were significantly decreased in our patients. The level of the dopamine metabolite, homovanillic acid, was also significantly reduced (P < 0.01). Also significantly decreased was 5-hydroxyindoleacetic acid (P < 0.01). Substance P was significantly elevated (P < 0.05). Somatostatin was significantly decreased (P < 0.05). We hypothesize that the sum of complex neurochemical changes plays a role in the pathogenesis of trigeminal neuralgia. The elevated substance P could support the concept of a neurogenic inflammation in the trigeminovascular system, whereas changes in the monoaminergic transmitters and their metabolites seem to reflect a more central dysfunction possibly due to a longer duration of the disease and an accompanying depression.

Somatostatin, its molecular forms and monoaminergic transmitter metabolites in Binswanger's disease. Neurochemical-neuropathological considerations

Cerebrospinal fluid (CSF) concentrations of somatostatin-like immunoreactivity (SLI), high molecular weight form somatostatin (HMV-SST), somatostatin-25/28 (SST-25/28), somatostatin-14 (SST-14), Des-ala-somatostatin (Des-ala-SST), homovanillic acid (HVA) and 5-hydroxyindoleacetic acid (5-HIAA) were measured in 21 patients with Binswanger's dementia (BD). Patients were classed into three stages of intellectual deterioration according to the Global deterioration scale (GDS). Levels of SLI were significantly decreased in patients suffering from BD, compared to a control group (19.7 +/- 11.6 fmol/ml vs. 30.5 +/- 8.6 fmol/ml, P < 0.01). There was no correlation with dementia scores (r = 0.34, P = 0.51). The observed qualitative and quantitative changes in the molecular pattern of SLI suggest that occurrence of a dysregulated posttranslational processing in patients with BD. Whereas 5-HIAA levels were not significantly changed in patients with BD, HVA was significantly increased in mild to moderate dementia (GDS 2-4) and significantly decreased in severe cases (GDS 7) (224.3 +/- 69.9 nmol/ml vs. 364.9 +/- 103.8 nmol/ml, P < 0.01); this correlated with dementia scores (r = -0.59, P < 0.01). The existence of significant correlations between SLI, 5-HIAA and HVA in BD point to a heterogeneous and generalized neurochemical process affecting several transmitter systems and functions.

CSF substance P somatostatin and monoaminergic transmitter metabolites in patients with narcolepsy

We have measured the concentrations of substance P, somatostatin, homovanillic acid (HVA), vanillyl mandelic acid (VMA) and 5-hydroxyindoleacetic acid (5-HIAA) in the cerebrospinal fluid (CSF) of six patients suffering from narcolepsy and 12 age- and gender-matched controls using high pressure liquid chromatography (HPLC) and radioimmunoassay (RIA). Substance P and somatostatin were significantly decreased in our patients compared to controls (36.9 +/- 9.1 fmol/ml versus 52.5 +/- 9.9 fmol/ml, P < 0.05 and 30.3 +/- 7.8 fmol/ml versus 43.9 +/- 9.8 fmol/ml, P < 0.05, respectively). 5-HIAA (P < 0.05) and VMA (P < 0.05) were also significantly decreased. HVA was significantly increased (P < 0.01). The CSF concentrations of substance P and somatostatin correlated with the clinical parameters duration of disease (r = -0.68, P < 0.05 and r = -0.72, P < 0.05, respectively) and severity of cataplectic symptoms (r = -0.71, P < 0.05 and r = -0.78, P < 0.01). In addition, substance P correlated with the intensity of sleepiness and the frequency of day-sleep attacks (r = -0.69, P < 0.05 and r = -0.68, P < 0.05, respectively). Substance P affects the amount of dopamine release in the nigra-striatal region, and decreased amounts could contribute to the pathogenesis of narcolepsy. Reduced levels of substance P, which affects serotonin release, may be responsible for diminished release of serotonin which in turn could affect sleep cycles. Because somatostatin affects motor behavior through dopaminergic mechanisms and since the levels of somatostatin correlate with the intensity of cataplectic symptoms, we speculate that an interaction between somatostatin and dopaminergic neurons plays a role in the pathogenesis of narcolepsy.

Low cerebrospinal fluid concentrations of peptide histidine valine and somatostatin-28 in Alzheimer's disease: altered processing of prepro-vasoactive intestinal peptide and prepro-somatostatin

Recent studies have indicated that deposition of beta amyloid peptide in the brains of patients with senile dementia of the Alzheimer type (SDAT) is a consequence of abnormal processing of the beta amyloid protein precursor. In addition, reduced concentrations of various peptides have been measured in post-mortem brain tissue and cerebrospinal fluid (CSF) of patients with SDAT. We determined concentrations of the peptides derived from prepro-vasoactive intestinal peptide (VIP)--peptide histidine methionine-27 (PHM-27), peptide histidine valine (PHV) and VIP--and peptides derived from prepro-somatostatin (prepro-SS), SS-14 and SS-28, in CSF of patients with SDAT by radioimmunoassay combined with high performance liquid chromatography. We found significantly reduced levels of total PHM-immunoreactivity (IR) and PHV, and unaltered levels of PHM-27 and VIP in SDAT, compared with those in controls. Total SS-IR and SS-28 concentrations were significantly reduced in SDAT, while SS-14 levels did not differ from those of controls. These results suggest that an altered processing of the prepro-peptides of VIP and SS may occur in SDAT and that these alterations might have a significant role in the pathogenesis of SDAT.

Elevation of CSF somatostatin concentrations in mania

OBJECTIVE

The aim of this study was to compare levels of CSF somatostatin (somatotropin release-inhibiting factor) in drug-free patients with different major psychiatric disorders.

METHOD

CSF somatostatin concentrations were measured in 66 drug-free inpatients with Research Diagnostic Criteria diagnoses of schizophrenia, major depressive disorder, manic disorder, or schizoaffective disorder.

RESULTS

In comparison with both the patients with schizophrenia and the patients with schizoaffective disorder, the manic patients had markedly elevated CSF somatostatin concentrations. The depressed patients had significantly higher levels than the schizophrenic patients.

CONCLUSIONS

Mania is associated with relatively higher CSF somatostatin concentrations.

Tau protein concentrations in cerebrospinal fluid of patients with dementia of the Alzheimer type

Tau protein concentrations were measured in the CSF of 23 patients with dementia of the Alzheimer type (DAT), 36 patients with multi-infarct dementia (MID), and 23 control subjects. Tau protein concentrations were significantly higher in patients with DAT than in controls (P < 0.001) and patients with MID (P < 0.001). A significantly positive correlation between CSF tau protein and glucose concentrations (r = 0.79, P < 0.001) and evolution of disease (r = 0.47, P < 0.05), and a negative correlation with Folstein's mental state examination test (r = -0.73, P < 0.001) were found in patients with DAT.

Cerebrospinal fluid neuropeptides in Alzheimer's disease and vascular dementia

Cerebrospinal fluid (CSF) levels of several neuropeptides have been suggested as candidate markers in neurodegenerative disorders. We have examined the levels of corticotropin-releasing hormone (CRH), beta-endorphine (BEND), delta sleep-inducing peptide (DSIP), somatostatin (SRIF), and neuropeptide Y (NPY) in CSF samples obtained under highly standardized conditions from healthy aged controls and from patients suffering from Alzheimer's disease (AD) or vascular dementia (VAD). The influence of some potentially confounding factors was evaluated. CRH and BEND were markedly decreased in both AD and VAD patients, and BEND levels correlated negatively with degree of dementia within the patient population. SRIF was decreased in both AD and VAD patients. DSIP was slightly increased in AD, but not in VAD. NPY did not differ between groups. For none of the peptides did CSF concentrations correlate significantly with duration of illness, nor, with the exception of BEND, with its degree. Present data do not support the hypothesis that specific neuropeptide changes occur in different neurodegenerative disorders, but are in agreement with previous reports suggesting that neuropeptide systems are differentially affected by neurodegeneration.

Nimodipine increases CSF somatostatin in affectively ill patients

Preliminary evidence suggests that nimodipine, an L-type calcium channel blocker, is effective in treating some patients with rapidly cycling affective disorders and some phases of Alzheimer's disease, i.e., two syndromes associated with transient or permanent reductions in cerebrospinal fluid (CSF) somatostatin, respectively. CSF somatostatin (SRIF) was measured in 14 affectively ill patients while they were medication-free and during chronic nimodipine treatment. CSF somatostatin significantly increased in patients during active nimodipine treatment compared with ones in the medication-free state. The current findings raise the possibility that nimodipine-induced increases in CSF somatostatin could potentially contribute to its spectrum of efficacy on neuropsychiatric disorders associated with cognitive or affective impairment. Further clinical and preclinical studies are indicated to elucidate the potential mechanisms involved in the elevation of CSF SRIF, whether it is reflected in regional changes in brain, and its possible relevance to nimodipine's clinical actions.

CSF somatostatin increase in patients with early parkinsonian syndrome

Somatostatin-like immunoreactivity levels (SLI) in cerebrospinal fluid (CSF) were determined in twenty-three patients with untreated parkinsonian syndrome (15 with Idiopathic Parkinson's disease (IPD) and 8 with other forms of parkinsonism) at the moment of clinical diagnosis (mean duration of disease 1.1 +/- 0.2 years), and in 26 subjects without neurological symptoms. None of the IPD patients had a diagnosis of dementia at the moment of inclusion in the study. CSF-SLI content was found to be significantly higher in patients with parkinsonian syndrome (107.9 +/- 9.8 pg/ml) than in control subjects (73.5 +/- 8.4 pg/ml). The increase was also significant when controls were compared with IPD patients. In addition, a positive correlation between SLI and homovanillic acid was found in CSF of all patients. A test of learning memory was used to evaluate the mental state of patients and a significant increase in CSF-somatostatin levels was observed in patients with Idiopathic Parkinson's disease and severe affectation of memory. These results indicate that in the early steps of untreated parkinsonian syndrome, somatostatin concentration in cerebrospinal fluid may increase, probably due to the neurodegenerative depletion of somatostatin from striatal or cortical neurons.

Cerebrospinal fluid and plasma concentrations of SRIH, beta-endorphin, CRH, NPY and GHRH in obese and normal weight subjects

Numerous hypothalamic peptides are involved in the control of eating behaviour. We assessed plasma and cerebrospinal fluid (CSF) levels of SRIH, beta-endorphin (beta-EP), CRH, NPY and GHRH in a group of massively obese patients and in normal weight subjects. In the obese patients, CSF SRIH and beta-EP levels were significantly reduced and increased, respectively, compared with controls (20.6 +/- 2.62, mean +/- s.e.m., vs 34.5 +/- 2.14 pg/ml, P < 0.05, for SRIH and 111.2 +/- 5.00 vs 80.4 +/- 5.32 pg/ml, P < 0.001, for beta-EP). Considering the data of obese and control subjects altogether, SRIH and beta-EP concentrations correlated negatively and positively, respectively, with BMI values (r = -0.641, P < 0.005 and r = 0.518, P < 0.05). No significant differences were observed in CSF levels of CRH, NPY and GHRH between obese and normal weight subjects, though GHRH levels were close to the assay sensitivity. CSF concentrations of CRH were positively correlated with those of SRIH in obese patients (r = 0.60, P < 0.05) and with those of NPY both in obese (r = 0.69, P < 0.02) and in control subjects (r = 0.83, P < 0.005). Plasma levels of SRIH, beta-EP, NPY and GHRH did not differ significantly in the two groups of subjects; plasma CRH was undetectable. Our results argue against the hypothesis of an enhanced SRIH tone as the cause of impaired GH secretion in obese patients, a primary defect in GHRH or GH release seems more likely. Moreover, they emphasise the importance of an increased tone of endogenous opioids in the pathophysiology of human obesity.

Changes in cerebrospinal fluid neurochemistry during treatment of obsessive-compulsive disorder with clomipramine

BACKGROUND

This study examined the effect of long-term (mean, 19 months) treatment with clomipramine hydrochloride on cerebrospinal fluid (CSF) levels of several neuropeptides and monoamine metabolites in children and adolescents with obsessive-compulsive disorder.

METHODS

The CSF levels of corticotropin-releasing hormone, vasopressin, somatostatin, and oxytocin and of the monoamine metabolites 5-hydroxyindoleacetic acid, homovanillic acid, and 3-methoxy-4-hydroxyphenylglycol were measured in 17 children and adolescents with obsessive-compulsive disorder before and after long-term treatment with clomipramine.

RESULTS

Treatment resulted in significant decreases in CSF levels of corticotropin-releasing hormone (mean +/- SD, 175 +/- 32 vs 152 +/- 25 pmol/L, P < .03) and vasopressin (mean +/- SD, 1.30 +/- 0.57 vs 0.86 +/- 0.54 pmol/L, P < .02) and a trend toward a decrease in somatostatin levels (mean +/- SD, 21.3 +/- 8.5 vs 15.3 +/- 9.8 pmol/L, P < .06). Treatment also significantly increased CSF oxytocin levels (mean +/- SD, 6.05 +/- 1.60 vs 6.70 +/- 1.44 pmol/L, P < .01). Significant changes in CSF monoamine metabolite levels with treatment included significant decreases in CSF levels of 5-hydroxyindoleacetic acid (mean +/- SD, 109 +/- 31 vs 77 +/- 23 pmol/mL, P < .001), CSF homovanillic acid (mean +/- SD, 273 +/- 111 vs 237 +/- 101 pmol/mL, P < .04), and 3-methoxy-4-hydroxyphenylglycol (mean +/- SD, 42.4 +/- 10.2 vs 36.1 +/- 4.8 pmol/L, P < .02) and a significant increase in the homovanillic acid-5-hydroxyindoleacetic acid ratio (mean +/- SD, 2.44 +/- 0.46 vs 3.42 +/- 0.84, P < .0001).

CONCLUSIONS

These neuropeptide results coupled with evidence that central administration of corticotropin-releasing hormone, vasopressin, and somatostatin to laboratory animals increases arousal and acquisition of conditioned behaviors whereas central administration of oxytocin has opposite behavioral effects are consistent with a role for these neuropeptides in the pathophysiologic processes and pharmacologic treatment of obsessive-compulsive disorder.

Study of the external counterpulsation (ECP) therapy for senile dementia of the Alzheimer's type (SDAT)

Ten patients with SDAT received the ECP therapy. The examination of Hasegawa's Dementia Scale (HDS), single photor emission computed tomography (SPECT) brain imaging, and some biochemical parameters in blood and CSF were selected to evaluate the effect of ECP for SDAT. After ECP treatment, the average HDS score of the patients increased, the value of P was close to 0.05; and the cortical cerebellar ratios of SPECT brain scan, the superoxide dismutase (SOD) activity and the concentrations of somatostatin-like immunoreactivity (SLI), dynorphin AL-13 (Dyn Al-13) in blood and/or CSF were significantly elevated. The results indicated that ECP could not only improve cerebral blood flow, but also make a notable impact on biological active substances in blood and CSF. It is suggested that ECP is beneficial to SDAT patients.

Cerebrospinal fluid somatostatin concentrations in schizophrenia and schizoaffective disorder: the effects of antipsychotic treatment

The authors examined the effects of antipsychotic treatment on cerebrospinal fluid somatostatin like immunoreactivity (CSF SLI) in 14 schizophrenic and 3 schizoaffective patients. There was a modest but significant increase in CSF SLI in 13 out of the 14 schizophrenic patients. In addition, there was a significant positive correlation between duration of treatment and post-treatment CSF SLI concentrations. No differential response was noted in patients also treated with the anticholinergic benztropine.

Effect of sulpiride or paroxetine on cerebrospinal fluid neuropeptide concentrations in patients with chronic tension-type headache

In lumbar cerebrospinal fluid (CSF) obtained from patients with chronic tension-type headache (CTH), the concentrations of beta-endorphin, met-enkephalin, dynorphin, cholecystokinin (CCK), calcitonin gene-related peptide (CGRP), and somatostatin were measured before and after 8 weeks of treatment with sulpiride or paroxetine. We previously reported higher than normal met-enkephalin concentrations in CTH. The present study reveals normal basal concentrations of CCK, CGRP and somatostatin and slightly decreased dynorphin in the same patients. Treatment with sulpiride or paroxetine did not change the concentration of any of the neuropeptides measured. These data suggest central changes in opioid systems but not in other peptide systems (CCK, CGRP, somatostatin) involved in nociceptive processing at the level of the spinal cord dorsal horn/nucleus caudalis of the trigeminal nerve in CTH. Such central changes might be pathophysiologically important or merely secondary to other more important occurrences. The lack of changes in neuropeptide concentrations during drug treatment makes planning of studies involving CSF analysis easier, but also limits the probability of obtaining information on specific neuropeptide systems through CSF analysis.

Secretion of growth hormone and thyroid-stimulating hormone in patients with dementia

We studied the growth hormone (GH) response to GH-releasing hormone (GHRH) and the thyroid-stimulating hormone (TSH) response to thyrotropin-releasing hormone (TRH) in four groups of patients with dementia and examined whether GH and TSH secretion is altered in patients with Alzheimer's disease. The four groups included those with Alzheimer's disease (n = 28), parkinsonism with dementia (n = 10), progressive supranuclear palsy with dementia (n = 10), and dementia of vascular origin (n = 28). The results showed no differences among the four groups in GH response to GHRH (12.2 +/- 2, 10.7 +/- 2, 8.9 +/- 1.1, and 9.9 +/- 1.9 micrograms/ml, respectively); there was no correlation between GH response to GHRH and sex, stage of the disease, or cerebral atrophy. The proportion of patients with exaggerated, normal, or lower GH response was similar in the four groups in terms of TSH response to TRH (9.2 +/- 0.9, 11.1 +/- 1, 11.1 +/- 1, and 10.3 +/- 1 mU/ml, respectively), nor was there a correlation between TSH response to TRH and sex, stage of the disease, cerebral atrophy, or GH response to GHRH. The proportion of those with exaggerated, normal, or lower TSH response was similar in the four groups. Cerebrospinal somatostatin levels were similar in Alzheimer's disease and vascular dementia patients. These findings indicate that neither GH response to GHRH nor TSH response to TRH provides a useful diagnostic adjunct in Alzheimer's disease patients.

Straight leg raising test and lumbar cerebrospinal fluid levels of vasoactive intestinal polypeptide and somatostatin in patients with low back pain

STUDY DESIGN

Straight leg raising was recorded before myelography in 77 patients. At myelography, samples of cerebrospinal fluid were drawn and later analyzed for neuropeptides vasoactive intestinal polypeptide and somatostatin.

OBJECTIVES

The study sought to examine correlations, if any, between a positive straight leg raising test and cerebrospinal fluid neuropeptide levels.

METHODS

The straight leg raising test was recorded for all patients before a myelography examination was performed because of intractable leg pain symptoms. Forty-seven of the patients were men and 30 were women. Cerebrospinal fluid samples were obtained from all patients upon myelography. Levels of the neuropeptides vasoactive intestinal polypeptide and somatostatin were analyzed in a blind manner by radioimmunoassay, using commercially available radioimmunoassay kits.

RESULTS

The results are compatible with previous observations that suggest cerebrospinal neuropeptide levels are altered in conjunction with neural injury or pain syndromes. In the present mixed back pain patient population, which included radicular pain symptoms due to disc herniation and lumbar stenosis, alterations in vasoactive intestinal peptide levels in particular were observed with a positive straight leg raising test.

CONCLUSIONS

Nerve root injury, as suggested by a positive straight leg raising test, appears to be neurochemically linked to altered cerebrospinal fluid vasoactive intestinal peptide levels.

A long-term follow-up study of cerebrospinal fluid somatostatin in delirium

Cerebrospinal fluid somatostatin-like immunoreactivity (CSF SLI) was determined for elderly delirious patients during the acute stage and after 1- and 4-year follow-up periods, and the SLI levels were compared with age-equivalent controls. As a whole group, and also when the group was subdivided according to the severity of cognitive decline at the acute stage, type of delirium or the central nervous system disease, delirious patients showed significant reduction of SLI as compared with the controls. In the follow-up, we observed a further reduction of CSF SLI together with significant correlations in the second, third and fourth samples between SLI levels and Mini-Mental State Examination scores. Our results suggest a role for somatostatinergic dysfunction in the genesis of some symptoms of delirium, and this dysfunction may be linked to the long-term prognosis of delirious patients.

Relationship of interleukin-1 beta and beta 2-microglobulin with neuropeptides in cerebrospinal fluid of patients with dementia of the Alzheimer type

We studied interleukin-1 beta (IL-1 beta), beta 2-microglobulin (beta 2-m), beta-endorphin, substance P, neuropeptide Y and somatostatin concentrations in the cerebrospinal fluid of 13 patients with dementia of the Alzheimer type (DAT), 13 patients with multi-infarct dementia (MID) and 15 age-matched control subjects. Substance P was significantly lower in DAT than in controls (P < 0.05), as well as somatostatin in DAT as compared to both controls (P < 0.01) and MID (P < 0.05), whereas beta 2-m was higher in DAT than in controls (P < 0.01). Neuropeptide Y, beta-endorphin and IL-1 beta showed similar concentrations in the three groups studied. A significantly positive correlation was observed between IL-1 beta and substance P (r = 0.79, P < 0.01) and somatostatin (r = 0.75, P < 0.05) in DAT, which was not observed in MID. In addition, beta 2-m showed a negative correlation with IL-1 beta (r = -0.73, P < 0.05) in DAT, and age correlated negatively with IL-1 beta in controls and MID, but positively in DAT. Therefore, these results support the idea that an altered relationship may exist in Alzheimer's disease between the nervous and immune system.

Peptide histidine methionine in cerebrospinal fluid of patients with senile dementia of the Alzheimer type

Immunoreactivities (IRs) of peptide histidine methionine (PHM) as well as somatostatin and vasoactive intestinal peptide (VIP) in the cerebrospinal fluid (CSF) were measured in patients with senile dementia of the Alzheimer type (SDAT) and age-matched control subjects. We found statistically significant reductions in the PHM-IR and somatostatin-IR levels in the CSF from patients with SDAT, as compared with those of the controls. However, the VIP-IR level in the CSF from SDAT was not different from that of the controls. These results suggest that selective degeneration of neurons containing somatostatin and PHM or the alteration in metabolism of PHM in the CSF might occur in SDAT.

CSF somatostatin in obsessive-compulsive disorder

OBJECTIVE

Because the central administration of somatostatin to experimental animals produces behaviors with some similarities to the compulsions of patients with obsessive-compulsive disorder and because serotonin reuptake inhibitors have been reported to reduce brain content of somatostatin, the authors examined central somatostatin activity in patients with obsessive-compulsive disorder.

METHOD

CSF for measurement of somatostatin was obtained from 15 drug-free outpatients with obsessive-compulsive disorder and 27 normal volunteers.

RESULTS

The mean CSF somatostatin level was significantly higher in the patients with obsessive-compulsive disorder than in the normal subjects.

CONCLUSIONS

Although the functional significance of this finding is unknown, these data are consistent with a role for somatostatin in the clinical symptomatology of obsessive-compulsive disorder and its response to neuropharmacological agents. The high levels of CSF somatostatin reported here in a patient subgroup whose predominant symptoms consisted of overly focused, perseverative thought processes are in contrast to the consistently low levels of CSF somatostatin seen in patients with a spectrum of disorders characterized by substantial cognitive deficits.

CSF somatostatin in Alzheimer's disease and major depression: relationship to hypothalamic-pituitary-adrenal axis and clinical measures

Patients with Alzheimer's disease (AD) and major depression have been shown to have overlapping clinical symptoms and biological markers, including decreased concentrations of cerebrospinal fluid (CSF) somatostatin-like immunoreactivity (SLI), which may be related to alterations in the hypothalamic-pituitary-adrenal axis activity. As in prior studies, we found that CSF SLI was significantly decreased in a group of AD patients (N = 49) and a group of elderly patients with major depression (N = 18), as compared with 13 age-matched controls (F[2, 77] = 12.9, p < .001). In the present study, CSF SLI and CSF corticotropin-releasing factor correlated significantly within the group of AD patients (r = 0.49, p < .0004) and almost attained significance in the depressed patients (r = 0.47, p < .07). CSF SLI correlated significantly with urinary free cortisol within each patient group (r = -0.51, p < .03). Clinical measures of dementia severity and depression did not consistently correlate with CSF SLI in either patient group.

Neuropeptides in relation to suicidal behavior in depression

Neuropeptides were examined in relation to suicidal behavior and its repetition in depression. There were no significant differences between depressed patients who had or had not attempted suicide for cerebrospinal fluid (CSF) concentrations of neuropeptide Y, somatostatin, diazepam-binding inhibitor, GABA, or corticotropin releasing hormone. A 5-year follow-up was carried out. There were no significant differences between depressed patients who did or did not reattempt suicide during the follow-up or who had never attempted for CSF concentrations of any of the neuropeptides measured. These negative results suggest that these neuropeptides are probably not major determinants of suicidal behavior or its repetition in depression.

Cerebrospinal fluid immunoreactive somatostatin concentrations in patients with Cushing's disease and major depression: relationship to indices of corticotropin-releasing hormone and cortisol secretion

To further explore the differential effects of peripherally and centrally derived hypercortisolism on neurohormonal systems implicated in the pathophysiology of mood and cognitive disturbances, we examined the cerebrospinal fluid (CSF) concentrations of immunoreactive somatostatin (IR-SRIF) in patients with Cushing's disease and major depression and the relationship of these levels to CSF immunoreactive corticotropin-releasing hormone (CRH) concentrations and urinary free cortisol excretion. In particular, since CSF SRIF levels consistently have been shown to be reduced in depression, we wished to assess whether decreased centrally directed SRIF was more likely a primary or a secondary factor in the hypercortisolism of major depression. CSF SRIF levels were significantly reduced in 11 patients with documented Cushing's disease and in 1 patient with ectopic adrenocorticotropic hormone secretion as compared with both 41 healthy volunteers (19.4 +/- 2.9 vs. 37.4 +/- 1.5 pmol/l; p < 0.01) and 28 patients with major depression (30.2 +/- 2.4 pmol/l; p < 0.05), whose CSF SRIF levels were also significantly reduced as compared with controls (p < 0.05). CSF SRIF levels in the Cushing's disease patients correlated positively with CSF CRH (r = 0.64; p < 0.025), suggesting that either the sustained hypercortisolism in these patients and/or its suppression of central CRH secretion contributed to the reduction in SRIF. A more modest but significant correlation between CSF SRIF and CSF CRH was observed in the healthy volunteers (r = 0.37; d.f. = 37; p < 0.02); in the depressed patients, no linear relationship, but rather an inverted U-shaped relationship was found which significantly fit by a quadratic function (r2 = 0.90; d.f. = 22; p < 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Somatostatin in the cerebrospinal fluid of schizophrenic patients before and after neuroleptic drug treatment

A radioimmunoassay procedure was used to determine levels of somatostatin-like immunoreactivity in cerebrospinal fluid obtained from 9 schizophrenic patients, 7 patients with other psychiatric disorders, and 10 nonpsychiatric surgical controls. There were no significant differences in mean somatostatin baseline levels between the schizophrenic, nonschizophrenic, and surgical patients. The concentration remained almost unaltered after 4 weeks of zuclopenthixol treatment in the schizophrenia group and following various neuroleptic, antidepressant, and anxiolytic medications in the nonschizophrenic patients despite a significant decrease of overt psychopathology assessed by the Brief Psychiatric Rating Scale.

Somatostatin concentrations in cerebrospinal fluid and brain tissue of patients with refractory epilepsy

The somatostatin concentrations of cerebrospinal fluid (CSF) and brain tissue in 16 refractory epileptic patients were measured simultaneously by a radioimmunoassay (RIA) method. An increased level of somatostatin was found in the epileptic foci of cerebral cortex, determined by the cortical EEG. There were significant differences among the epileptic foci (75.58 +/- 6.58 pg/mg wet wt, +/- SEM), nonfocal tissues (37.04 +/- 6.55 pg/mg), and normal tissues of control patients (47.69 +/- 10.12 pg/mg), p < 0.001 and p < 0.05, respectively. The somatostatin concentrations of CSF in 11 epileptic patients were determined before (257.78 +/- 19.11 pg/mL) and after (178.36 +/- 8.78 pg/mL) the removal of epileptic focal area, and a dramatic decrease of the CSF somatostatin concentration after operation was detected (p < 0.01). We also found that the somatostatin level of cerebral scar induced by head injury in cases of posttraumatic epilepsy was highest (106.39 +/- 12.41 pg/mg). The results suggested that the surgical removal of the epileptic focal area in refractory epileptic patients may reduce the increased central somatostatin level, which could play an important part in the pathophysiological process of refractory epilepsy.

Long-term treatment with carbamazepine affects CSF somatostatin immunoreactivity in epileptic patients

A number of pharmacological evidence supports the view that somatostatin (SS) may be importantly involved in the seizure susceptibility both in humans and in laboratory animals. In a previous report the Authors have provided the finding that a short-term carbamazepine (CBZ) administration is able to reduce SS-CSF-IR in epileptic patients. The present study has been carried out to investigate whether a long-term treatment with CBZ affects in a similar way SS-IR content in CSF from temporal lobe epileptics (CPS). The results confirm and expand previous evidence suggesting that CBZ lowering effect on CSF-SS-IR may be relevant to its anticonvulsivant action.