Recommendations of the Sleep Study Group of the Italian Dementia Research Association (SINDem) on clinical assessment and management of sleep disorders in individuals with mild cognitive impairment and dementia: a clinical review

Clinical assessment and management of sleep disturbances in patients with mild cognitive impairment and dementia has important clinical and social implications. Poor sleep results in an increased risk of morbidities and mortality in demented patients and is a source of stress for caregivers. Sleep disturbances show high prevalence in mild cognitive impairment and dementia patients and they are often associated one to another in the same patient. A careful clinical evaluation of sleep disorders should be performed routinely in the clinical setting of individuals with cognitive decline. The Sleep Study Group of the Italian Dementia Research Association (SINDem) reviewed evidence from original research articles, meta-analyses and systematic reviews published up to December 2013. The evidence was classified in quality levels (I, II, III) and strength of recommendations (A, B, C, D, E). Where there was a lack of evidence, but clear consensus, good practice points were provided. These recommendations may not be appropriate for all circumstances and should therefore be adopted only after a patient's individual characteristics have been carefully evaluated.

Prevalence of sleep disturbances in mild cognitive impairment and dementing disorders: a multicenter Italian clinical cross-sectional study on 431 patients

BACKGROUND/AIMS

Sleep disturbances are common in the elderly and in persons with cognitive decline. The aim of this study was to describe frequency and characteristics of insomnia, excessive daytime sleepiness, sleep-disordered breathing, REM behavior disorder and restless legs syndrome in a large cohort of persons with mild cognitive impairment or dementia.

METHODS

431 consecutive patients were enrolled in 10 Italian neurological centers: 204 had Alzheimer's disease, 138 mild cognitive impairment, 43 vascular dementia, 25 frontotemporal dementia and 21 Lewy body dementia or Parkinson's disease dementia. Sleep disorders were investigated with a battery of standardized questions and questionnaires.

RESULTS

Over 60% of persons had one or more sleep disturbances almost invariably associated one to another without any evident and specific pattern of co-occurrence. Persons with Alzheimer's disease and those with mild cognitive impairment had the same frequency of any sleep disorder. Sleep-disordered breathing was more frequent in vascular dementia. REM behavior disorder was more represented in Lewy body or Parkinson's disease dementia.

CONCLUSION

A careful clinical evaluation of sleep disorders should be performed routinely in the clinical setting of persons with cognitive decline. Instrumental supports should be used only in selected patients.

Prior antiplatelet therapy and outcome following intracerebral hemorrhage: a systematic review

OBJECTIVES

Antiplatelet therapy (APT) promotes bleeding; therefore, APT might worsen outcome in patients with intracerebral hemorrhage (ICH). We performed a systematic review and meta-analysis to address the hypothesis that pre-ICH APT use is associated with mortality and poor functional outcome following ICH.

METHODS

The Medline and Embase databases were searched in February 2008 using relevant key words, limited to human studies in the English language. Cohort studies of consecutive patients with ICH reporting mortality or functional outcome according to pre-ICH APT use were identified. Of 2,873 studies screened, 10 were judged to meet inclusion criteria by consensus of 2 authors. Additionally, we solicited unpublished data from all authors of cohort studies with >100 patients published within the last 10 years, and received data from 15 more studies. Univariate and multivariable-adjusted odds ratios (ORs) for mortality and poor functional outcome were abstracted as available and pooled using a random effects model.

RESULTS

We obtained mortality data from 25 cohorts (15 unpublished) and functional outcome data from 21 cohorts (14 unpublished). Pre-ICH APT users had increased mortality in both univariate (OR 1.41, 95% confidence interval [CI] 1.21 to 1.64) and multivariable-adjusted (OR 1.27, 95% CI 1.10 to 1.47) pooled analyses. By contrast, the pooled OR for poor functional outcome was no longer significant when using multivariable-adjusted estimates (univariate OR 1.29, 95% CI 1.09 to 1.53; multivariable-adjusted OR 1.10, 95% CI 0.93 to 1.29).

CONCLUSIONS

In cohort studies, APT use at the time of ICH compared to no APT use was independently associated with increased mortality but not with poor functional outcome.

Polysomnographic characterization of pergolide-induced sleep attacks in idiopathic PD

Both dopamine agonists and levodopa may induce episodes termed "sleep attacks" in patients with PD. These episodes are well detailed behaviorally, but little is known about their neurophysiologic characterization. The authors performed a 24-hour polysomnography (PSG) in a PD patient taking pergolide in combination with levodopa, in which four of these diurnal sleep episodes occurred. PSG findings were followed up after pergolide withdrawal. Sleep episodes shared with narcolepsy both behavioral and EEG findings. However, pergolide partly restored a more physiologic sleep architecture, which was disrupted during therapy with levodopa alone.

Primary intraventricular haemorrhage in adults

INTRODUCTION

Primary intraventricular haemorrhage (PIVH) is an uncommon type of intracerebral haemorrhage. Relatively little is known about clinical and imaging features, and even less about prognosis and predictors of mortality.

MATERIAL AND METHODS

We analysed clinical and imaging features, causative factors and outcome of 26 patients with CT brain scan evidence of PIVH. A multivariate regression model of failure time data was used to assess predictors of in-hospital mortality.

RESULTS

Loss of consciousness was the first manifestation of PIVH in six patients and occurred after all other symptoms in five. In other patients, onset was characterized by headache, vomiting, confusion and disorientation (n=8) or by headache with or without vomiting (n=7). Angiography revealed vascular malformations in eight patients (31%). Other possible causative factors were clotting disorder in one patient and arterial hypertension in 10. No cause was identified in seven patients. Early hydrocephalus was the most frequent complication and resolved spontaneously in a minority of patients. In-hospital mortality was high (42%): four patients died early of direct consequence of bleeding and seven died after clinical worsening because of increasing hydrocephalus or other adverse events. Multivariate analysis indicated Glasgow Coma Scale < or = 8 (OR 4.67; 95% CI 1.22-17.92) and early hydrocephalus (OR 4.93; 95% CI 1.13-21.59) as independent predictors of in-hospital mortality.

CONCLUSION

In patients with PIVH, hydrocephalus seems to be a critical determinant of in-hospital mortality and this suggests the need for early treatment strategies.

Potential triggering factors of intracerebral hemorrhage

The distributions of intracerebral hemorrhage (ICH) according to place of onset, degree of physical activity at onset and potential triggering factors were analyzed in 848 patients with ICH. Patients were grouped according to the presumed cause of ICH: hypertensive ICH, secondary ICH and ICH of undetermined origin. The influence of demographic and temporal factors on the relative frequency of events was also assessed. In 30% of the cases, ICH occurred during inactivity or sedentary activity, in 50% during light exertion and in 20% during moderate/vigorous exertion. During inactivity or sedentary activity, hypertensive ICH was significantly less frequent than secondary ICH (OR 0.32; 95% CI 0.21-0.47) and undetermined ICH (OR 0.36; 95% CI 0.23-0.55), whereas during moderate or vigorous exertion hypertensive ICH was more frequent than secondary (OR 1.88; 95% CI 1.16-3.05) and undetermined ICH (OR 2.29; 95% CI 1.31-4.00) Potential triggering factors were observed in 27% of patients and were significantly more frequent in patients with hypertensive ICH than in patients with secondary ICH (OR 2.90; 95% CI 1.85-4.54) or undetermined ICH (OR 2.44; 95% CI 1.54-3.87). Our findings suggest that many potential external triggers that act mainly by raising blood pressure may interact, and their concurrence may favor cerebral hemorrhage, particularly in hypertensive patients. In many cases, these circumstances of increased risk may be mitigated by preventive measures.

Somatosensory processing during movement observation in humans

OBJECTIVES

A neural system matching action observation and execution seems to operate in the human brain, but its possible role in processing sensory inputs reaching the cortex during movement observation is unknown.

METHODS

We investigated somatosensory evoked potentials (SEPs), somatosensory evoked fields (SEFs) and the temporal spectral evolution of the brain rhythms (approximately 10 and approximately 20 Hz) following electrical stimulation of the right median nerve in 15 healthy subjects, during the following randomly intermingled conditions: a pure cognitive/attentive task (mental calculation); the observation of a motoric act (repetitive grasping) with low cognitive content ('Obs-grasp'); and the observation of a complex motoric act (finger movement sequence), that the subject had to recognize later on, therefore reflecting an adjunctive cognitive task ('Obs-seq'). These conditions were compared with an absence of tasks ('Relax') and actual motor performance.

RESULTS

The post-stimulus rebound of the approximately 20 Hz beta magnetoencephalographic rhythm was reduced during movement observation, in spite of little changes in the approximately 10 Hz rhythm. Novel findings were: selective amplitude increase of the pre-central N(30) SEP component during both 'Obs-grasp' and 'Obs-seq', as opposed to the 'gating effect' (i.e. amplitude decrease of the N(30)) occurring during movement execution. The strength increase of the 30 ms SEF cortical source significantly correlated with the decrease of the approximately 20 Hz post-stimulus rebound, suggesting a similar pre-central origin.

CONCLUSIONS

Changes took place regardless of either the complexity or the cognitive content of the observed movement, being related exclusively with the motoric content of the action. It is hypothesized that the frontal 'mirror neurons' system, known to directly facilitate motor output during observation of actions, may also modulate those somatosensory inputs which are directed to pre-central areas. These changes are evident even in the very first phases (i.e. few tens of milliseconds) of the sensory processing.

Provocative tests in different stages of carpal tunnel syndrome

The frequency of positive results of four conventional provocative tests (Phalen sign, Tinel sign, wrist extension and pressure provocation test) was evaluated in 179 patients with clinical and electrophysiological findings consistent with idiopathic carpal tunnel syndrome (CTS), 147 control subjects and 39 patients with polyneuropathy. The diagnostic accuracy was evaluated for each test alone and in combination and the sensitivity correlated with the clinical and electrophysiological severity of CTS. For comparison of the CTS group with the control group, none of the tests reached sufficient diagnostic accuracy. The same was found for comparison of the CTS group with the polyneuropathy group, the Tinel sign being the least accurate. The combination of signs was not found to be more useful than single signs. The sensitivity of all signs was much less in severe clinical stages of CTS, especially for tests that increase the intra-carpal canal pressure. Traditional provocative tests, such as those tested here, have limited or no value for distinguishing patients with and without CTS, one reason being that their sensitivity depends largely on the clinical and electrophysiological severity of CTS. This correlation may also explain the contradictory results in the literature.

Brain-stem compression in vertebrobasilar dolichoectasia. A multimodal electrophysiological study

OBJECTIVE

To evaluate the effects of mechanical compression of the brain-stem in patients with vertebrobasilar dolichoectasia (VBD).

METHODS

In the framework of a prospective, observational study that collected clinical and laboratory data in patients with VBD, we studied 20 patients with compression of the brain-stem due to ectatic, tortuous basilar or vertebral arteries. Patients with cerebral lesions other than small lacunae in the white matter of the cerebral hemispheres were excluded from the study. Patients underwent vestibular and auditory function testing, including brain-stem auditory evoked potentials (BAEPs), blink reflex (BR), somatosensory evoked potentials (SEPs), and motor evoked potentials (MEPs).

RESULTS

Almost all of the patients complained of auditory or vestibular symptoms and none had symptoms or signs of impairment of long tracts or the facial and trigeminal nerves. The most consistent findings were BR abnormalities with prolongation of ipsilateral R1 latency in cases of compression of the pons (10/16) and prolongation of the R2 and R2c latencies with compression of the medulla oblongata (5/15). Subclinical impairment of corticospinal pathways was found in 13 out of 25 instances of compression, and this was more frequent with compression of the pons. Abnormal BAEPs or SEPs were less frequently encountered, and only in cases with compression of the pons.

CONCLUSIONS

Neurovascular compression of the brain-stem, even with severe distortion, is seldom associated with overt clinical signs, whereas subclinical dysfunctions are relatively frequent. The central pathways of the BR and the corticospinal pathways are more susceptible to compression than acoustic and sensory pathways. BR, MEP and BAEP data provide a functional evaluation of the brain-stem and some cranial nerves, which is lacking in imaging studies. Functional investigations may be useful in the long-term management of these patients, since VBD may be progressive and surgical correction may be required at some stage.

Differing temporal patterns of onset in subgroups of patients with intracerebral hemorrhage

BACKGROUND AND PURPOSE

The purpose of this study was to further analyze the temporal patterns of onset of intracerebral hemorrhage (ICH) and to determine whether or not subgroups with specific clinical characteristics exhibit different patterns of onset.

METHODS

The daily, weekly, and yearly variations in occurrence of ICH together with the relationship between ICH occurrence and changes in air temperature were evaluated in 1018 patients. Patients were grouped according to the presumed etiology of ICH: hypertensive ICH, secondary ICH, and ICH of undetermined origin. The contribution of demographic and clinical factors to the temporal distributions of ICH was also evaluated.

RESULTS

Marked differences in seasonal and diurnal patterns of ICH onset were observed in the different groups. The incidence of hypertensive ICH reflected seasonal and circadian changes in blood pressure, whereas the latter did not seem related to the onset of nonhypertensive ICH. The seasonal pattern was more evident in elderly patients with hypertensive ICH than in younger subjects. No significant weekly variations were observed; however, risk was greater on Monday in the working population.

CONCLUSIONS

Our results suggest that the higher incidence of ICH in the colder months is due to the effect of low temperatures on blood pressure and that the clustering of ICH events in the morning is due to the increase in sympathetic tone, and consequent increase in blood pressure, on awakening.

Time course of frontal somatosensory evoked potentials. Relation to L-dopa plasma levels and motor performance in PD

OBJECTIVE

To verify whether the change in L-dopa plasma levels after a single dose of carbidopa/L-dopa 50/200 (controlled-release) transiently modifies frontal components of somatosensory evoked potentials (SEPs) in patients with PD in parallel with improvement of motor performance.

BACKGROUND

Apomorphine, a potent dopamine-agonist drug, transiently increases frontal SEP components, which may be depressed in PD; however, relationships between clinical status, frontal SEPs, and therapy are still unclear.

METHODS

Nineteen PD patients (mean age 65.9 years, range 52 to 77, responders to L-dopa therapy, were studied in the same day at times T0 (baseline predose level), T1 (presumed L-dopa peak time), and T2 (end of dose-induced motor response). The following were monitored: L-dopa plasma concentration, tapping test, reaction times, peak latency (with central conduction times), and amplitude of cervical, subcortical, as well as cortical parietal and frontal SEP components elicited by median nerve stimulation of the more clinically affected arm.

RESULTS

The average amplitude of frontal components of PD patients was significantly reduced at T0 with respect to control subjects. A significant and transient amplitude increase of frontal SEPs was found at T1, in parallel with the L-dopa peak concentration and improvement in motor performance (tapping and reaction times), without significant changes in amplitude of parietal SEP waves. No latency shifts were observed in brain and spinal waves.

CONCLUSIONS

L-Dopa may influence the responsiveness of the parkinsonian brain as assessed by frontal somatosensory evoked potentials. The time course of these modifications coincides with that of the clinical response in the motor performance.

Multifocal neural conduction impairment in forestry workers exposed and not exposed to vibration

OBJECTIVE

The aim of the study was to assess peripheral neural involvement induced by exposure to hand-arm vibration.

METHODS

Twenty lumberjacks, working regularly with chain-saws and exposed to hand-arm vibration (group E) and 20 forestry workers performing heavy manual work and not exposed to vibration (group NE) were matched with a control group of 20 healthy non-manual workers (group C). The subjects of groups E and NE, all symptomatic, and of group C underwent extensive bilateral neurophysiological examination consisting of: sensory conduction (velocity and amplitude) of radial, median and ulnar nerves in digit-wrist segments; sensory conduction (velocity) of median nerve in wrist-elbow segment; mixed conduction (velocity and amplitude) of median and ulnar nerves in palm-wrist segments; motor conduction velocity, including distal motor latencies, and amplitude of median (elbow-wrist) and ulnar (elbow-wrist and across the elbow) nerves.

RESULTS

Electrophysiological abnormalities were found in 85% of group E's limbs, versus 62.5% of group NE's limbs. The most frequent pathological pattern in group E was a 'multifocal' impairment (multiple sites of several nerve segments), with a prevalent involvement of sensory rather than motor fibres in the hand, seldom extending to the forearm. Multivariate analysis showed that the neurographic parameters which better characterized workers exposed to hand-arm vibration had a pattern different from that usually found in idiopathic carpal tunnel syndrome (CTS).

CONCLUSION

These results suggest that vibration-induced neural involvement can be considered neither pure digital neuropathy, nor definite CTS, as previously described.

Posterior circulation infarcts in patients with vertebrobasilar dolichoectasia

BACKGROUND AND PURPOSE

Vertebrobasilar dolichoectasia (VBD) may produce symptoms by direct compression of cranial nerves or the brain stem, by obstructive hydrocephalus, or by ischemia in the vertebrobasilar arterial territory. This study was undertaken to examine and characterize clinical and imaging findings in patients with stroke associated with VBD and compare these data with those for patients with VBD who did not have a stroke.

METHODS

We studied 40 consecutive stroke patients with associated VBD. All were evaluated by CT scan (n=9), MRI (n=6), or both (n=25). The diameter of the basilar artery (BA), height of bifurcation, and transverse position were evaluated. Clinical and imaging findings were compared with those found in a group of 40 VBD patients without stroke.

RESULTS

More than half of the patients (24 of 40) had infratentorial infarcts, located mainly in the midpons. Sixteen patients had supratentorial lesions localized in the thalamus (n=8) or in the superficial arterial territory of the posterior cerebral artery (PCA; n=8). The diameter and height of the bifurcation of the BA were correlated with the location of the lesion (PCA territory versus BA territory), in that severe ectasia and vertical elongation of the BA were significantly more often observed in patients with infarcts in PCA territory than in patients with infarcts in territories supplied by branches of the BA. Comparison of VBD patients with and without stroke showed that the incidence of arterial hypertension and the degree of ectasia and lateral displacement of the BA were not significantly different in the two groups. Patients with stroke more often had atherosclerotic changes of the posterior circulation (P=.0006) and a higher degree of vertical elongation of the BA (P=.025).

CONCLUSIONS

In patients with VBD, superimposed atheromatous changes of the posterior circulation may have an important role in precipitating ischemia. However, other factors related to the severity of the dolichoectasia also favor ischemia and in some cases are the only factors responsible.

Bilateral Vestibular Loss in Vertebrobasilar Dolichoectasia

Bilateral vestibular loss (BVL) is a relatively uncommon syndrome that may produce problems of balance; unsteady gait, especially in the dark; and visual disorders and/or oscillopsia associated with walking and head movements. Sometimes patients with BVL remain asymptomatic. Ototoxic drugs are the most frequently identified cause of BVL, but there are many other possible causes. The aetiology remains unknown in a large percentage of patients. In some, vascular aetiology may be suspected. Here we report 4 cases of vertebrobasilar dolichoectasia (VBD) and symptomatic BVL. In 3 subjects, hearing was preserved, but in the 4th, there was retrolabyrinthine hearing loss. In our opinion, VBD may be the cause of BVL associated or not associated with hearing loss, the reason being that since the anterior vestibular artery is small and has no anastomoses, the horizontal semicircular canal is selectively susceptible to ischemia.

Bilateral vestibular loss in vertebrobasilar dolichoectasia

Bilateral vestibular loss (BVL) is a relatively uncommon syndrome that may produce problems of balance; unsteady gait, especially in the dark; and visual disorders and/or oscillopsia associated with walking and head movements. Sometimes patients with BVL remain asymptomatic. Ototoxic drugs are the most frequently identified cause of BVL, but there are many other possible causes. The aetiology remains unknown in a large percentage of patients. In some, vascular aetiology may be suspected. Here we report 4 cases of vertebrobasilar dolichoectasia (VBD) and symptomatic BVL. In 3 subjects, hearing was preserved, but in the 4th, there was retrolabyrinthine hearing loss. In our opinion, VBD may be the cause of BVL associated or not associated with hearing loss, the reason being that since the anterior vestibular artery is small and has no anastomoses, the horizontal semicircular canal is selectively susceptible to ischemia.

Auditory and vestibular system findings in patients with vertebrobasilar dolichoectasia

Impairment of the auditory-vestibular system has been reported in patients with vertebrobasilar dolichoectasia (VBD), but little is known about the underlying cause of the symptoms. Auditory testing (pure tone audiometry, auditory brain stem response and stapedius reflex) and vestibular tests (assessment of nystagmus, eye tracking tests, caloric test and rotational test) were performed in 23 patients with auditory-vestibular symptoms and/or cranial nerve impairment associated with VBD. Specific evidence of auditory and/or vestibular system impairment was observed in 19 cases (83%). Among patients with abnormal test findings, 47% had evidence suggesting peripheral impairment, 16% evidence suggesting central dysfunction, and 37% evidence suggesting both peripheral and central dysfunction. Although compression of the vestibulocochlear nerve plays an important role in the genesis of the auditory-vestibular dysfunction in patients with VBD, mechanism such as brain stem-cerebellar ischemia and impaired blood supply to the vestibular labyrinth may be just as important.

Effects of acyclovir on sensory axonal neuropathy, segmental motor paresis and postherpetic neuralgia in herpes zoster patients

The effect of oral treatment with acyclovir (ACV) on sensory axonal neuropathy, segmental motor paresis and postherpetic neuralgia (PHN) was studied in 105 patients with herpes zoster. Forty-seven patients were treated with ACV at a dose of 4 g/day in 5 doses for at least a week; the others did not undergo any kind of treatment. Electrodiagnostic examination of the nerves and muscles corresponding to the dermatomeric lesions was performed, including sensory and motor nerve conduction studies, blink reflex and electromyography (EMG). The patients treated with ACV showed a significant reduction in the number of cases in which there was electrophysiological evidence of axonal damage in afferent fibres of nerves arising from roots corresponding to affected dermatomes. The treated group also showed a smaller incidence of segmental motor neuritis, clinically evident or only detectable by EMG as denervation. However, there was no significant difference between groups as far as the incidence of PHN was concerned. Oral treatment with ACV therefore reduces peripheral sensory axonopathy due to ganglion damage and prevents the possibility of spread to anterior roots and spinal motoneurones. In this way it reduces the incidence of segmental motor neuritis, but does not reduce the incidence of PHN.

Recurrence of bleeding in patients with primary intracerebral hemorrhage

BACKGROUND AND PURPOSE

Rebleeding in patients with primary intracerebral hemorrhage is considered uncommon, but there are no precise data to support this opinion. The purpose of this study was to assess the incidence and predictors of recurrent bleeding in survivors of primary intracerebral hemorrhage.

METHODS

As part of a prospective study, 112 survivors of a first primary intracerebral hemorrhage were followed up for a mean period of 84.1 months after their discharge. To ascertain risk factors that may influence rebleeding, several demographic, medical history, clinical, and laboratory variables were collected and analyzed.

RESULTS

Twenty-four percent (27/112) of survivors experienced one or more rebleeding during the follow-up period, in 8 cases (30%) in the first year of follow-up; in the others recurrence occurred later, up to 11.5 years. Rebleeding had a high mortality rate: 70% of patients died as a consequence of their second or third hemorrhage. Univariate and multivariate analyses showed that lobar location of the first hemorrhage was the only significant predictor of rebleeding. Patients with rebleeding were more frequently older, more often had a history of previous transient ischemic attack or ischemic stroke, and less often had hyperlipidemia than patients without rebleeding, although these correlations did not reach statistical significance. During follow-up, poor control of arterial hypertension was found in 7% of hypertensive patients without rebleeding and in 47% of hypertensive patients with rebleeding.

CONCLUSIONS

Our study showed that rebleeding after a first primary intracerebral hemorrhage is not as uncommon as is usually believed. The risk of rebleeding seems to be particularly high after hemorrhage at the junction of the gray and white matter, a site regarded as typical of hemorrhages due to amyloid angiopathy, and when arterial hypertension is poorly controlled.

Regional cerebral blood flow changes following chronic administration of antidepressant drugs

1. Twenty-six patients with major unipolar depression were rated clinically and regional cerebral blood flow (rCBF) determined prior to and after six months of treatment with 75-100 mg/day amitriptyline (n. 16) or 200 mg/day amineptine (n. 10). 2. rCBF was measured in 16 regions over each hemisphere by the Xenon 133 inhalation method and was computed as the initial slope index (ISI). The severity of depression was quantified by the Hamilton rating scale for depression. 3. Baseline rCBF values of depressed patients tended to be lower than those of normal subjects. Significant reductions were observed for all probes exploring the frontal region of the left hemisphere and for some probes exploring the frontal region of the right hemisphere. Chronic treatment with amitriptyline induced a significant increase in rCBF in the left frontal region. Similar results were obtained after treatment with amineptine. 4. Besides confirming frontal lobe dysfunction in depressed patients which is reversed by treatment with classic tricyclic antidepressants, the present results show that this dysfunction may also be reversed by treatment with dopaminergic drugs.

Quantitative EEG mapping, regional cerebral blood flow, and neuropsychological function in Alzheimer's disease

The relations between quantitative EEG, regional cerebral blood flow (rCBF), severity of disease and neuropsychological data were analyzed in 31 patients in different stages of Alzheimer's disease (AD). As a group the demented patients had higher delta and theta activities, lower alpha activity and lower alpha peak frequency than control subjects. rCBF was reduced in all regions studied but mainly in the temporoparietal areas. An analysis of correlations showed a close relationship between rCBF and certain quantitative EEG parameters in AD patients, mainly the power of the theta and delta bands. Both rCBF evaluation and quantitative EEG provide functional information related to the severity of cognitive impairment.

Cervical and scalp recorded short latency somatosensory evoked potentials in response to epidural spinal cord stimulation in patients with peripheral vascular disease

Somatosensory evoked potential (SEP) studies were performed in 14 patients with peripheral vascular disease who received epidural spinal cord stimulation (SCS) for chronic pain relief of the lower limbs. Signals were amplified and filtered between 20-2000 Hz and 200-2000 Hz to better identify activities in the high frequency range. In 7 patients bit-colour maps were also computed. In all the patients a homogeneous short-latency scalp evoked potential with a prevalent diphasic shape (P1-N1) was recorded. In all our scalp records, even with the wide bandpass, small short-latency positive deflections were observed on the descending front of the first major positive wave and they were better defined as a series of up to 6 wavelets, preceding the major negative scalp wave in the tracings filtered through the narrow bandpass. They appeared in an interval ranging from 5.5 to 15.6 msec. Bit-colour maps showed consistent positive fields, with a maximum at the vertex, starting mainly at about 5.5 msec; in 3 patients, a prominent positivity between 8.5 and 10.5 msec was recorded followed by smaller components preceding the major positive-negative (P1-N1) complex. More synchronous volleys during direct SCS produced clear short-latency SEPs. Although they were of larger amplitude, we regarded them as corresponding to those described by previous authors obtained by stimulation of nerves of the lower limbs, and probably arising from subcortical structures.

Sensory neural conduction of median nerve from digits and palm stimulation in carpal tunnel syndrome

The median sensory nerve conduction between ring finger and wrist is a suitable parameter for early detection of carpal tunnel syndrome (CTS), although shorter segments of median nerve have also been proposed for the same goal. In order to assess the relative diagnostic value of the sensory nerve conduction velocity (SNCV) of the third palmar branch versus the SNCV of the second palmar branch, generally performed until now, we studied 62 patients with typical signs and symptoms of CTS. The following parameters were evaluated by surface recording: orthodromic SNCVs in digit-wrist segments for median (index = M2, third = M3 and ring = M4 fingers), ulnar (fourth = U4 finger) and radial (thumb = R1) nerves; SNCVs in palm-wrist segments by surface bipolar stimulation at each metacarpo-phalangeal interspace (second = P2 and third = P3 for the median nerve and fourth = P4 for the ulnar nerve); and distal motor latencies of the median and ulnar nerves. No responses at the wrist were recorded in 22.6% of patients after digital stimulation of M4, whereas the SNCV of P3, the palmar nerve branch arising from digital nerves of the medial side of M3 and the lateral side of M4, was measurable in 93.5% of patients. As significantly expressed (P < 0.001) by the increased ratio of the mean values of P2 and P3 in CTS patients, the SNCV of P3 decreased more frequently and to a greater extent than the SNCV of P2.

Diagnosis of thoracic outlet syndrome. Relative value of electrophysiological studies

The diagnostic utility of various electrophysiological techniques was evaluated in patients with thoracic outlet compression syndrome (TOCS). Our results suggest that in true neurogenic TOCS, there is no standard electrophysiological picture, but that this evolves with the severity of the syndrome. The first changes observed are electromyographic, followed by changes in F-wave and SEPs, followed finally by changes in nerve conduction parameters. EMG study was certainly more informative, showing neurogenic damage not only in limbs with neurological signs but also in about 1/4 of limbs with only subjective symptoms. The study of F-wave and SEPs does not seem to be particularly helpful, however, in view of the peculiar changes found in these patients, SEPs may be a useful complement to EMG. Nerve conduction studies were of little utility since changes in these parameters are only found in patients with long-standing anomalies and severe atrophy.

An electromyographic evaluation of motor complications in thoracic herpes zoster

Motor complications in thoracic herpes zoster were evaluated in 52 patients by electromyographic examination of the paraspinal muscles. At the initial EMG examination, abnormal findings were observed in 18 patients (35%). In 8 patients the myomers involved coincided in location with affected dermatomes, while in 10 patients, in addition to the involvement of myomers corresponding to affected dermatomes, there also appeared an involvement of one or more contiguous myomers not corresponding to affected dermatomes. Our study demonstrated that motor involvement in thoracic HZ is much more common than previously suggested and its incidence (35%) appears to be greater than that reported in both cervical and lumbosacral HZ.

Involvement of peripheral sensory fibers in amyotrophic lateral sclerosis: electrophysiological study of 64 cases

We report electrophysiological findings of conduction along peripheral sensory fibers in 64 patients with amyotrophic lateral sclerosis. Distribution of the values of action potential amplitudes and conduction velocities of peripheral afferent fibers were significantly lower than in normal age-matched controls. Sensory action potential amplitudes (SAPas) were more affected than sensory conduction velocities (SCVs). When single patients were considered, SAPas were slightly but significantly reduced in 22% of the cases (median nerve 17%, ulnar nerve 11%, and sural nerve 22%). A parallel decrease in SCVs and MCVs in 14 patients in whom the study was repeated over a period of time was also found. All these electrophysiological findings are due to progressive neuronopathy of peripheral sensory fibers. A pathogenetic mechanism is proposed.

[Maps of somatosensory evoked potentials from the arm in patients with neoplasms and post-traumatic brain lesions]

Short-latency somatosensory evoked potentials by the stimulation of the median nerve at the wrist, were recorded in six patients (four with cerebral tumors and two with post-trauma lesions). The electrodes were placed on the scalp following the 10-20 International System. A reference electrode was placed on earlobe contralateral to the site of the stimulation. Eleven normal subjects were used as control (mean age 64.4 +/- 12.05). We used the Brain-Surveyor-Basis Trade system which allowed us to elaborate the results by coloured mapping through linear interpolation of signal amplitudes. The following parameters were investigated: peak latencies of the N13, N20, P22, N30 waves; amplitudes of the post-rolandic P14-N20, N20-P25, pre-rolandic P22-N30 components and the central conduction time N13-N20 (CCT). The evaluation of latencies was not significant in determining the lesion site. On the contrary, the evaluation of amplitudes revealed expressive asymmetry, though it did not define the nature of alteration (increase or decrease due to lesion), and the correlation between these variations and the site of the lesion. The authors discussed the possibility that amplitude abnormalities in patients with tumors were related either to the tumors and/or drug effects.

[CAT and MRI in the study of partial epilepsy: comparison of the 2 methods and correlations with EEG]

Seventy five adult patients suffering from partial epilepsy were investigated by MRI. Results were then compared with those obtained with CT scan and EEG analysis. The interval between the two neuroradiological studies did not exceed five years. MRI and CT showed abnormalities respectively in 45 and 55% of patients, MRI showed a better sensitivity in detecting ischemic or atrophy-gliosis chronic focal alterations. In the remaining lesions such as tumors, vascular malformations, cysts and diffuse atrophies, where often an urgent diagnosis is necessary, both tests were equally sensitive. EEG showed alterations in 80% of patients and agreed with results of CT scan and MRI in about 80% of cases.

[Ophthalmoparesis as a presentation form of subacute euthyroid thyroiditis]

The present study describes a case of subacute thyroiditis characterized by involvement of ocular motility that appeared many months before bioumoral findings of the disease. The authors believe that when the etiological diagnosis of an ophthalmoparesis, especially when isolated, is uncertain, one must carefully evaluate the function of the thyroid and levels of the specific antibodies, in order to start the appropriate treatment.

Electrophysiologic evaluation of local steroid injection in carpal tunnel syndrome

Extensive sensory and motor nerve conduction studies were performed in a series of patients with electrophysiologically proven, idiopathic carpal tunnel syndrome who were treated by a single steroid injection (40 mg of triamcinolone acetonide). Electrophysiologic studies, which included evaluation of median, ulnar, and radial orthodromic sensory action potentials, median and ulnar motor action potentials, and electromyography of two intrinsic muscles of the hand, were done before and at 45 days and six months after the treatment. By the end of the follow-up period, the symptoms had remitted completely in 11 hands (35%), 18 (58%) benefitted from partial relief, and two did not improve. In addition to the relief of symptoms, abnormalities of motor nerve conduction improved in 65% of cases, and abnormalities of sensory nerve conduction improved in 73% of all the individual digital branches of the median nerve examined. Recovery of function of the median nerve continued for a long period, even after the pharmacologic effect of the steroid agent had presumably ceased.

[Palm stimulation in carpal tunnel syndrome]

In order to verify the sensory nerve conduction velocity (SNCV) by median nerve palmar stimulation regard to each single finger, we tested 48 patients with typical CTS symptoms, confirmed by neurophysiological examination. The control group consisted of twenty-seven healthy volunteers, of similar mean age. The SNCVs were obtained by stimulating the II finger (M2), III (M3), IV (M4) and II and III intermetacarpo-phalangeal site (respectively P2 and P3) for median nerve; IV finger (U4) and IV intermetacarpophalangeal site (P4) for ulnar nerve. Data show that P2 was normal in 3 cases (6.2%), as was M2; M3 in 2 cases (4.2%) and P3 only in one case (2.1%). No sensory nerve action potential was recorded in 3 case (6.2%) during P3 stimulation, in comparison to 14 cases (29.2%) during M4 stimulation. When each case was examined separately, the behaviour of palmar SNCV resulted similar to the corresponding fingers. Finally, the ratio between SNCV values of P2/P3, with respect to controls, showed a further more severe damage of P3 compared to the P2, generally preferred by other authors.

Arachnoid cysts of the middle cranial fossa: a clinical, radiological and follow-up study

Twenty-seven patients with CT-scan-diagnosed arachnoid cysts in the middle cranial fossa were studied. Five (18%) presented with progressive symptoms related to raised intracranial pressure which had developed after minor trauma and secondary bleeding, 12 (44%) presented with non-progressive symptoms, and 10 (37%) exhibited neurological syndromes not referable to the cyst. Among those with non-progressive symptoms, epilepsy was the most common presentation (67%). More than 60% of the cysts were small and limited to the anterior temporal region or to the Sylvian fissure, the remaining cysts involved both the anterior temporal region and the Sylvian fissure, and expanded to the adjacent fronto-temporal or fronto-parietal regions. The volume measurements of the brain tissue performed on CT scan revealed that between the volume of the two hemispheres there was no significant difference suggesting any evidence of agenesis or hypoplasia of the affected temporal lobe.

Diagnostic specificity of sensory and motor nerve conduction variables in early detection of carpal tunnel syndrome

In the carpal tunnel syndrome (CTS) sensory nerve conduction is more sensitive than motor conduction. However, 8%-25% of the sensory distal latencies in symptomatic hands may still be normal. A systematic study was made of the median, ulnar and radial orthodromic nerve conduction velocities (SNCV) stimulating each of the fingers separately. Four SNCVs from the median nerve, two SNCVs from the ulnar nerve and one from the radial nerve were obtained, and the ratio of the median to radial SNCV and the ratios of the median and ulnar SNCVs were estimated. The significance of these parameters in the diagnosis of the CTS was studied, and a rapid technique for the screening of nerve entrapment in the initial stages of the disease is proposed. Three hundred and seventy-five symptomatic hands were examined. Seventy-five hands showed normal distal latency, in which cases, however, the SNCV of the ring finger was always outside the normal range, while the SNCVs of the thumb, index and middle fingers were abnormal in 64%, 80% and 92% of cases respectively. The amplitudes of the sensory responses were the least sensitive of the parameters studied. Our results suggest that a study of the median nerve digital branch to the ring finger may be of value in providing an easily performed and rapid technique for screening an early median nerve entrapment at the wrist.

Italian multicenter study of reversible cerebral ischemic attacks. Part 5. Risk factors and cerebral atherosclerosis

As part of a prospective study, the influence of several premorbid and environmental factors on the presence, extent and severity of cerebral vessel atherosclerosis was studied in 462 patients with clinical diagnosis of RIA who underwent cerebral angiography. The extent and severity of atherosclerosis of the cerebral vessels was quantified using extracranial and intracranial cerebrovascular scores (ECS, ICS) based on the number and severity of the lesions in 11 extracranial and 21 intracranial arterial segments. Results of univariate and multivariate analyses indicate that the presence of atherosclerotic changes of cerebral vessels, as shown by angiography, was strongly related with age in both sexes. The lesions were more frequent in males, in particular under age 55. Elevated cholesterol was associated with a higher incidence of atherosclerotic lesions. Smoking was associated with a higher incidence of extracranial lesions. Age, smoking and history of hypertension were the best predictors of the extent and severity of cerebral vessel atherosclerosis.

Toxic polyneuropathy of shoe workers in Italy. A clinical, neurophysiological and follow-up study

Cases of polyneuropathy due to exposure to industrial solvents have been studied at several shoe factories in the province of Siena. After the screening of 654 employees 98 verified cases were detected. Of these, 16 were rated as moderate to severe, 45 as mild, and 37 were minimally involved but with characteristic electrodiagnostic abnormalities. Follow-up study in 53 patients showed that neurological signs and symptoms as well as electrodiagnostic abnormalities continued for years in several patients. In addition, after a year's observation, some patients showed signs of central nervous system dysfunction such as spasticity of the lower limbs and increased deep tendon reflexes. High percentages of commercial n-hexane were found in all the samples of glues and solvents collected from home-workers and from factories where cases of polyneuropathy occurred.

Platelet embolism in rabbit brain

Transient cerebral ischemia was induced in rabbits by selective infusion of arachidonic acid (0.35 mg/kg in 15 sec) into the internal carotid artery. Platelet emboli caused transient ischemia of the brain, reaching a maximum within a few seconds after injection. After embolism the EEG flattened, blood flow stopped in almost the entire injected hemisphere, cortical pH gradually fell from 7.31 +/- 0.09 to 7.05 +/- 0.10 and cortical K+ activity rose from 4.7 +/- 1.8 to 12.7 +/- 6.4 mmol/kg H2O. Complete ischemia lasted 3-5 min; then cerebral circulation was gradually restored without reactive hyperemia. Forty-five min after embolization, circulation had been resumed in almost the entire injected hemisphere, whereas metabolic changes were still disturbed. Eighty percent of the animals recovered complete neurological function and 20% showed permanent damage confirmed by histological examination after 1 week of recovery.

Effect of pentoxifylline on cerebral blood flow in patients with chronic cerebrovascular disease

The effect of pentoxifylline on cerebral blood flow (CBF) was studied with the intravenous 133Xe clearance technique in eleven patients with chronic cerebrovascular disease. Pentoxifylline was administered orally at a dose of 1200 mg/day over a period of 30 days (eight patients) or by intravenous infusion of 100 ml saline containing 400 mg of the drug in 1 hour (three patients). CBF was measured before and after pharmacological treatment. CBF was found to be significantly increased by both acute and chronic administration of pentoxifylline.

Depression of cerebral glucose utilization during animal hypnosis in the rabbit

The rates of local cerebral glucose utilization have been measured in normal conscious and hypnotized rabbits by the [14C]deoxyglucose method. In control rabbits the rates vary widely throughout the brain, with the values in gray matter broadly distributed around an average which is about 3 times greater than that of white matter. The higher values area in structures of auditory system (superior olive, inferior colliculus, auditory cortex). Animal hypnosis reduces the rates of glucose utilization in all structures of the rabbit brain, particularly in the caudate nucleus, putamen and sensory and motor cortices.

Animal model of TIA: an experimental study with intracarotid ADP infusion in rabbits

Adenosine diphosphate (8 mg per minute for five minutes) was infused into the carotid artery of 63 rabbits. The effects were twofold: systemic hypotension and platelet aggregation in the cerebral circulation. As a consequence of the last effect, platelet emboli were produced which occluded cerebral arteries in a number and size sufficient to cause cerebral ischemia. Areas of focal ischemia were observed through a cranial window, and documented with antipyrine autoradiography. Platelet thrombi were almost entirely transient, being fragmented and removed within a very short time of cessation of ADP infusion. Consequently, no permanent tissue damage ensued. This experimental model approaches the spontaneous transient ischemia attacks (TIAs) in man, demonstrating that these can be caused by pure platelet emboli. A high cholesterol diet administered for two months prior to ADP infusion did not enhance the effect of the procedure or make the platelet aggregation and the following ischemia longer in duration or more severe.