Total biopterin levels in the ventricular CSF of patients with Parkinson's disease: a comparison between akineto-rigid and tremor types

Quantification of Monoamine Neurotransmitter Metabolites and Cofactors in Cerebrospinal Fluid: State-of-the-Art

Inborn errors of monoamine neurotransmitter metabolism are rare diseases characterized by nonspecific neurological symptoms. These symptoms appear in early childhood and correspond to movement disorders, epilepsy, sleep disorders and/or mental disability. Cerebrospinal fluid biomarkers have been identified and validated to allow specific diagnosis of these diseases. Biomarkers of inborn errors of monoamine neurotransmitter metabolites are divided in two groups: monoamine neurotransmitter metabolites and pterins. Biomarkers quantification in cerebrospinal fluid is based on high-performance liquid chromatography separation coupled to electrochemical detection, fluorescence detection, or mass spectrometry. The following article reviews the advances in the proposed routine methods for the measurement of these analytes in cerebrospinal fluid. The purpose of this review is to compare the various proposed methods in terms of sample preparation, chromatographic conditions and detection modes. Despite the broad range of proposed methods, quantification of inborn errors of monoamine neurotransmitter biomarkers remains a great challenge, given the complexity of biological fluids and the low amounts of analytes that are present in cerebrospinal fluid.

Analeptic agent from microbes upon cyanide degradation

Microbes being the initial form of life and ubiquitous in occurrence, they adapt to the environment quickly. The microbial metabolism undergoes alteration to ensure conducive environment either by degrading the toxic substances or producing toxins to protect themselves. The presence of cyanide waste triggers the cyanide degrading enzymes in the microbes which facilitate the microbes to utilize the cyanide for its growth. To enable the degradation of cyanide, the microbes also produce the necessary cofactors and enhancers catalyzing the degradation pathways. Pterin, a cofactor of the enzyme cyanide monooxygenase catalyzing the oxidation of cyanide, is considered to be a potentially bioactive compound. Besides that, the pterins also act as cofactor for the enzymes involved in neurotransmitter metabolism. The therapeutic values of pterin as neuromodulating agent validate the necessity to pursue the commercial production of pterin. Even though chemical synthesis is possible, the non-toxic methods of pterin production need to be given greater attention in future.

Cerebrospinal fluid biochemical studies in patients with Parkinson's disease: toward a potential search for biomarkers for this disease

The blood-brain barrier supplies brain tissues with nutrients and filters certain compounds from the brain back to the bloodstream. In several neurodegenerative diseases, including Parkinson's disease (PD), there are disruptions of the blood-brain barrier. Cerebrospinal fluid (CSF) has been widely investigated in PD and in other parkinsonian syndromes with the aim of establishing useful biomarkers for an accurate differential diagnosis among these syndromes. This review article summarizes the studies reported on CSF levels of many potential biomarkers of PD. The most consistent findings are: (a) the possible role of CSF urate on the progression of the disease; (b) the possible relations of CSF total tau and phosphotau protein with the progression of PD and with the preservation of cognitive function in PD patients; (c) the possible value of CSF beta-amyloid 1-42 as a useful marker of further cognitive decline in PD patients, and (d) the potential usefulness of CSF neurofilament (NFL) protein levels in the differential diagnosis between PD and other parkinsonian syndromes. Future multicentric, longitudinal, prospective studies with long-term follow-up and neuropathological confirmation would be useful in establishing appropriate biomarkers for PD.

Surrogate endpoints in Parkinson's disease research

Biomarkers are important tools in understanding the underlying mechanisms of causation, progression, and treatment effects in Parkinson's disease (PD). In addition, these biomarkers may be utilized as surrogate endpoints that, when used appropriately, can lead to important advances in therapeutics in a timely and cost-effective manner. This paper outlines the definition, role, validity process, and risks associated with surrogate endpoints. The use of biomarkers in recent PD clinical trials is discussed and potential shortcomings and unanswered questions related to interpreting these outcomes are reviewed. Finally, the significant challenges that lie ahead for validating and interpreting surrogate endpoints in PD are addressed.

Involvement of apoptosis and calcium mobilization in tetrahydrobiopterin-induced dopaminergic cell death

Parkinson's disease is a neurodegenerative disorder associated with selective loss of the dopaminergic neurons in the substantia nigra. We have previously shown that tetrahydrobiopterin (BH4), the obligatory cofactor for dopamine synthesis, exerts selective toxicity on dopamine-producing cells. In the present study we determined, both in vitro and in vivo, whether the cell death induced by this endogenous molecule involves apoptosis, resembling that which occurs in Parkinson's disease. Transmission electron microscopic analysis revealed that the dopamine-producing CATH.a cells underwent ultrastructural changes typical of apoptosis, such as cell shrinkage and chromatin condensation, upon exposure to BH4. The BH4 treatment also caused intranuclear DNA fragmentation as determined by TUNEL staining. A similar phenomenon also occurred in vivo, as the nigral cells became TUNEL-positive upon injection of BH4 into the substantia nigra. The BH4-induced CATH.a cell death seemed to involve macromolecule synthesis because cycloheximide and actinomycin D had protective effects. Concurrent treatment with the caspase inhibitor Z-VAD-FMK also suppressed cell death. BH4 treatment led to increases in the ratio of Bax/Bcl-x(L) mRNA and protein levels. Ca(2+) seemed to play a role in BH4-induced cell death, because BH4 caused an increase in Ca(2+) uptake and the intracellular Ca(2+) release blocker dantrolene, intracellular Ca(2+) chelator BAPTA/AM, and extracellular Ca(2+) chelator EGTA each attenuated the toxicity. These data provide evidence that the dopaminergic cell death induced by BH4 involves apoptosis and suggest relevance of this cell death to degeneration of the dopaminergic system in Parkinson's disease.

Glutathione depletion in nigrostriatal slice cultures: GABA loss, dopamine resistance and protection by the tetrahydrobiopterin precursor sepiapterin

Dopaminergic neurons in culture are preferentially resistant to the toxicity of glutathione (GSH) depletion. This effect may be due to high intrinsic levels of tetrahydrobiopterin (BH(4)). Here we studied the effects of manipulating GSH and/or BH(4) levels on selective neurotoxicity in organotypic nigrostriatal slice cultures. Following treatments with L-buthionine sulfoximine (BSO, 10-100 microM, 2 days exposure, 2 days recovery), either alone or in combination with the BH(4) precursor L-sepiapterin (SEP, 20 microM), or the BH(4) synthesis inhibitor 2,4-diamino-6-hydroxypyrimidine (DAHP, 5 mM), toxic effects were assessed by HPLC analysis of medium and tissues, cellular propidium iodide (PI) uptake, lactate dehydrogenase (LDH) efflux, as well as stereological counting of tyrosine-hydroxylase (TH) positive cells. Thirty micromolar BSO produced 91% GSH and 81% GABA depletion and general cell death, but no significant effect on medium homovanillic acid (HVA) or tissue dopamine (DA) levels. SEP prevented or delayed GABA depletion, PI uptake and LDH efflux by BSO, whereas DAHP in combination with BSO caused (almost) complete loss of medium HVA, tissue DA and TH positive cells. We suggest that under pathological conditions with reduced GSH, impaired synthesis of BH(4) may accelerate nigral cell loss, whereas increasing intracellular BH(4) may provide protection to both DA and GABA neurons.

A cross-over clinical and electromyographic assessment of treatment for parkinsonian tremor

BACKGROUND

Whether dopaminergic and anticholinergic drugs exert influence on parkinsonian rest and postural tremor is a subject of debate. Different types of tremor may be influenced differently by the drugs. The aim of this study was to reevaluate the differential effects of levodopa and anticholinergic drugs on parkinsonian tremor in different limb positions and on different types of postural tremor.

METHODS

Thirty-eight patients with parkinsonian resting tremor and postural tremor were included in this study. Patients were divided into two groups according to the electromyographic pattern of the postural tremor. We found fast synchronous postural tremor (>7 Hz) in 16 patients, and slow alternating postural tremor in 22 patients. The tremor was scored clinically in each limb position using the Webster Tremor Scale. Surface electromyographic recordings from the most involved limb in all positions were also performed. The patients were randomly assigned to levodopa (one 250/50-mg tablet), or to biperiden (one 3-mg tablet). Tremor was assessed by clinical and electromyographic examinations at base line 1h following ingestion of the drug. The subjective tremor improvement was also assessed.

RESULTS

We found that levodopa had a good effect on the amplitude of the resting tremor, while the effect of biperiden was weaker. Both levodopa and biperiden has less effect on postural tremor. However, levodopa's effect was better than that of biperiden. Levodopa and biperiden had better effect on slow alternating postural tremor than on fast synchronous postural tremor. They had no effect on kinetic and intention tremors.

CONCLUSIONS

Levodopa and anticholinergic drugs have differing effects on both resting and postural tremor Also, the different categories of postural tremor respond differently to treatment. The mechanisms underlying resting parkinsonian tremor may be different from those underlying postural, kinetic and intention tremor. Moreover, the mechanisms underlying different types of postural tremor may be different.

CSF dopamine, serotonin, and biopterin metabolites in patients with restless legs syndrome

PURPOSE

To evaluate the role of CNS dopaminergic systems in Restless Legs Syndrome (RLS), homovanillic acid (HVA), tetrahydrobiopterin (BH4), and neopterin (NEOP), were assayed in CSF from RLS patients. The serotonin metabolite, 5-hydroxyindoleacetic acid (5-HIAA), was also measured.

METHODS

CSF was taken from 16 RLS patients after 2 weeks off medication and from 14 control subjects. The CSF metabolites were determined using HPLC techniques.

RESULTS

There was no significant difference in HVA or 5-HIAA, but NEOP and BH4 were higher in RLS patients. The RLS group was significantly older than the control group (64.2 +/- 9.2 years vs. 51.4 +/- 6.3 years; P < 0.001). A multiple regression analysis showed a strong correlation between age and 5-HIAA (r = 0.46, P = 0.04) and between age and NEOP (r = 0.61, P < 0.01). To eliminate the potential error created by the age difference between groups, an age-adjusted subgroup of RLS and control subjects were compared. There was still no difference found for HVA; however, 5-HIAA was now significantly lower (P < 0.01) in the RLS subgroup. Age-adjustment eliminated the differences previously found for NEOP, (P = 0.12), but BH4 continued to remain higher in the RLS group (P < 0.01).

CONCLUSION

Differences in CSF HVA concentrations were not found. The changes in 5-HIAA and BH4 are of unclear clinical significance and require further assessment with appropriate age-matched controls.

The role of 6R-tetrahydrobiopterin in the nervous system

In addition to its cofactor activities for aromatic L-amino acid hydroxylases and nitric oxide synthase (NOS), 6R-tetrahydrobiopterin (6R-BH(4)) shows diverse actions on neurons. Dopamine release from the rat striatum or PC12 cells was stimulated by 6R-BH(4). The action of 6R-BH(4) was independent of its cofactor activities and stereospecific. Ca(2+) channels in rat brain and PC12 cells were activated by 6R-BH(4) via cAMP-protein kinase A pathway. Membrane potential of PC12 cells was deplorized by 6R-BH(4). Thus, it is assumed that 6R-BH(4) acts on its specific action site (possibly outside of the cell membrane) to stimulate dopamine release by activating Ca(2+) channels. Apoptosis induced by depletion of serum and nerve growth factor in PC12 cells was prevented by 6R-BH(4). The cell surviving effect of 6R-BH(4) was also mediated by activation of Ca(2+) channels and cAMP-protein kinase A pathway. However, since 6R-BH(4) did not activate mitogen activated protein kinase, it did not support neuronal differentiation. Nitric oxide (NO)-induced cell death was prevented by 6R-BH(4) in PC12 cells. NOS activity was not changed by exogenous 6R-BH(4), but NO metabolites in culture medium were decreased by 6R-BH(4). When endogenous 6R-BH(4) was reduced by inhibition of biosynthesis, cell death was induced in PC12 cells. Superoxide is observed to be generated during autoxidation of 6R-BH(4). Superoxide producing system mimicked the cell protective action of 6R-BH(4) against NO toxicity. Thus, it is considered that 6R-BH(4) protects PC12 cells against NO toxicity by generating superoxide during its autoxidation. These results raised the possibility that 6R-BH(4) is a self-protective factor against NO toxicity in NO producing neurons. Our findings indicate that 6R-BH(4) regulates neuronal activities in the brain and that 6R-BH(4) can be a promising drug for neurodegenerative disorders such as Parkinson's disease and Alzheimer's disease.

A quantitative surface electromyogram analysis for diagnosis and therapy control in Parkinson's disease

Computer analysis of EMG data on tonic and phasic activities of mm. biceps and triceps brahii was performed to evaluate objectively Parkinson's disease (PD) symptoms and to quantify levodopa therapy effects. Fifteen patients were evaluated in the OFF and eleven in the ON states. Ten healthy controls were also studied. The following EMG parameters were examined: average and maximal amplitudes at rest, occurrence of burst muscle discharges (BMD) with a frequency of 4-7Hz, phasic activation coefficients (PhAC) of the voluntarily contracting flexors and reflex agonist/antagonist muscle involvement under voluntary movement or tonic strain. Statistically significant correlations of resting EMG amplitudes and PhACs with the part III UPDRS motor scores were found. However, the level of antagonist muscle involvement correlated specifically with the part II UPDRS and dyskinesia (disability) scores. Treatment with levodopa produced a clear positive effect on resting amplitudes, PhAC values and BMD occurrence. But in some cases levodopa caused an enhancement of agonist and antagonist muscle involvement, which may be an objective indicator of the risk for developing drug-induced dyskinesia in PD patients.

Post mortem studies in Parkinson's disease--is it possible to detect brain areas for specific symptoms?

Parkinson's disease (PD) is characterized by progressive neuronal loss associated with Lewy bodies in many subcortical nuclei leading to multiple biochemical and pathophysiological changes of clinical relevance. Loss of nigral neurons causing striatal dopamine deficiency is related to both the duration and clinical stages (severity) of the disease. The clinical subtypes of PD have different morphological lesion patterns: a) The akinetic-rigid type shows more severe cell loss in the ventrolateral part of substantia nigra zona compacta (SNZC) that projects to the dorsal putamen than the medial part projecting to caudate nucleus and anterior putamen, with negative correlation between SNZC cell counts, severity of akinesia-rigidity, and dopamine loss in the posterior putamen. Reduced dopaminergic input causes overactivity of the GABA ergic inhibitory striatal neurons projecting via the "indirect loop" to SN zona reticulata (SNZR) and medial pallidum (GPI) leading to inhibition of the glutamatergic thalamo-cortical motor loop and reduced cortical activation. b) The tremor-dominant type shows more severe neuron loss in medial than in lateral SNZC and damage to the retrorubral field A8 containing only few tyrosine hydroxylase and dopamine transporter immunoreactive (IR) neurons but mainly calretinin-IR cells. A8 that is rather preserved in rigid-akinetic PD (protective role of calcium-binding protein?) projects to the matrix of dorsolateral striatum and ventromedial thalamus. Together with area A10 it influences the strial efflux via SNZR to thalamus and from there to prefrontal cortex. Rest tremor in PD is associated with increased metabolism in the thalamus, subthalamus, pons, and premotor-cortical network suggesting an increased functional activity of thalamo-motor projections. In essential tremor, no significant pathomorphological changes but overactivity of cerebello-thalamic loop have been observed. c) In the akinetic-rigid forms of multisystem atrophy, degeneration is more severe in the lateral SNZC with severe loss of calbindin-IR cells reflecting initial degeneration of the striatal matrix in the caudal putamen with transsynaptic degeneration of striatonigral efferences that remain intact in PD. This fact and loss of striatal D2 receptors--as in advanced stages of PD--are reasons for negative response to L-dopa substitution. These data suggest different pathophysiological mechanisms of the clinical subtypes of PD that have important therapeutic implications. d) Involvement of extranigral structures in PD includes the mesocortical dopaminergic system, the noradrenergic locus coeruleus, dorsal vagal nucleus and medullary nuclei, serotonergic dorsal raphe, nucleus basalis of Meynert and other cholinergic brainstem nuclei, e.g. Westphal-Edinger nucleus (controlling pupillomotor function), posterolateral hypothalamus and the limbic system, e.g. amygdaloid nucleus, part of hippocampal formation, limbic thalamic nuclei with prefrontal projections, etc. Damage to multiple neuronal systems by the progressing degenerative process causing complex biochemical changes may explain the variable clinical picture of PD including vegetative, behavioural and cognitive dysfunctions, depression, pharmacotoxic psychoses, etc. Future comparative clinico-morphological and pathobiochemical studies will further elucidate the pathophysiological basis of specific clinical symptoms of PD and related disorders providing a broader basis for effective treatment strategies. Parkinson's disease (PD) is characterized by progressive degeneration of the nigrostriatal dopaminergic system and other subcortical neuronal systems leading to striatal dopamine deficiency and other biochemical deficits related to the variable clinical signs and symptoms of the disorder. (ABSTRACT TRUNCATED)

Chronic exposure to MPTP as a primate model of progressive parkinsonism: a pilot study with a free radical scavenger

The development of a validated primate model of progressive parkinsonism is a critical step in the evaluation of drugs that might halt or slow progression of Parkinson's disease. In this pilot study, we gradually exposed 14 cynomolgus monkeys to 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), at a weekly dose of 0.5 mg/kg s.c. for 10 weeks, to determine their probability of not reaching a predetermined endpoint on a disability scale by Kaplan-Meier analysis. Four other MPTP-exposed animals were coadministered the potent free radical scavenger 7-hydroxy-1-[4-(3-methoxyphenyl)-1-piperazinyl]acetylamino-2,2,4,6- tetramethylindan (OPC-14117) as a single oral daily dose of 0.6 g/kg, starting 2 weeks before MPTP initiation. The risk of reaching endpoint by week 10 was 79% and mean time before reaching endpoint was 6 weeks. Global motor activity, recorded in a subset of animals using a portable activity monitor, declined following the first MPTP dose and never recovered. Several cerebrospinal fluid indices of central monoamine metabolism collected by suboccipital puncture at 0, 5, and 10 weeks, including HVA, DOPAC, and tetrahydrobiopterin but not MHPG, were found to be "trait" markers for MPTP exposure, whereas CSF DOPAC and tetrahydrobiopterin constituted potential "state" markers for reaching endpoint. The antioxidant OPC-14117 did not protect against MPTP-induced parkinsonism. Further attempts to validate this incremental model of neurotoxin-induced parkinsonism as a predictor of patient responses to putative neuroprotective agents appear warranted.

Concentrations of indoleamine metabolic intermediates in the ventricular cerebrospinal fluid of advanced Parkinson's patients with severe postural instability and gait disorders

Postural instability and gait disorders (PIGD) are the primary causes of disability in many but not all advanced Parkinson's disease (PD) patients. We have measured the concentrations of serotonin, 5-hydroxytryptophan (5-HTP), 5-hydroxy-3-indoleacetic acid (5-HIAA), and homovanillic acid (HVA) in samples of ventricular cerebrospinal fluid from ten PD patients with severe disability from PIGD and from ten PD patients with tremor and levodopa induced dyskinesia as their predominant motor dysfunction. The two groups were prospectively matched for duration of disease and age. No significant differences between the two groups were found in the concentration (mean +/- SD in ng/ml, PIGD dominant vs. tremor-dyskinesia dominant) of 5-HIAA (106 +/- 50 vs. 99 +/- 34) or HVA (1,068 +/- 595 vs. 881 +/- 469). Serotonin concentration was significantly lower (0.7 +/- 0.5 vs. 1.5 +/- 0.9) and 5-HTP concentration was substantially higher (684 +/- 1,054 vs. 6 +/- 5) in the patient group with PIGD as their predominant symptoms. Thus, the distinguishing feature of patients with severe PIGD appears to be a derangement in indoleamine metabolism at the reaction step catalyzed by aromatic amino acid decarboxylase (AADC). These findings suggest that aggravation of PIGD in advanced Parkinson's may be related in part to impaired serotonergic transmission secondary to inhibition or down regulation of AADC.

Interleukin (IL)-1 beta, IL-2, IL-4, IL-6 and transforming growth factor-alpha levels are elevated in ventricular cerebrospinal fluid in juvenile parkinsonism and Parkinson's disease

Interleukin (IL)-1 beta , IL-2, IL-4, IL-6, epidermal growth factor (EGF), and transforming growth factor (TGF)-alpha were measured for the first time in ventricular cerebrospinal fluid (VCSF) from control non-parkinsonian patients, patients with juvenile parkinsonism (JP) and patients with Parkinson's disease (PD) by highly sensitive sandwich enzyme immunoassays. All cytokines were detectable in VCSF from control and parkinsonian patients, and the concentrations were much higher than those in lumbar CFS. The concentrations of IL-1 beta, IL-2, IL-4 and TGF-alpha in VCSF were higher in JP than those in controls (P < 0.05). In contrast, the concentrations of IL-2 and IL-6 in VCSF from patients with PD were higher than those from control patients (P < 0.05). These results agree with our previous reports, in which the cytokine levels were elevated in the striatal dopaminergic region of the brain from patients with PD. Since VCSF is produced in the ventricles, the alteration of cytokines in VCSF may reflect the changes of cytokines in the brain. Because cytokines play an important role as mitogens and neurotrophic factors in the brain, the increases in cytokines as a compensatory response may occur in the brain of patients of JP or PD during the progress of neurodegeneration. Increase in cytokines may contribute not only as a compensatory response but as a primary initiating trigger for the neurodegeneration.

Sulfamethoxazole-trimethoprim double-blind, placebo-controlled, crossover trial in Machado-Joseph disease: sulfamethoxazole-trimethoprim increases cerebrospinal fluid level of biopterin

We performed a double-blind, placebo-controlled, crossover trial of sulfamethoxazole-trimethoprim (S-T) in 8 patients with Machado-Joseph disease (MJD), and measured the blood and cerebrospinal fluid levels of biopterins, biogenic amines or metabolites, and folate. The clinical results were as follows; mild improvements of hyperreflexia of knee jerks and of rigospasticity of the legs during S-T treatment period. In addition, S-T significantly reduced the times of 8 motor activities on the timed tests. The biochemical results showed that basal levels of all biopterins and homovanillic acid in the cerebrospinal fluid (CSF) were reduced to less than half the levels of those of controls with other neurological diseases. After S-T treatment, total and oxidized form of biopterins in the CSF increased significantly. Therefore, S-T may be effective to neurologic deficits through its mechanism of increasing the level of brain biopterins.

Significance of CSF total neopterin and biopterin in inflammatory neurological diseases

Total neopterin (T-N), a by-product in the biopterin biosynthesis and an indicator of activation of the cellular immune system, and total biopterin (T-B) levels in cerebrospinal fluid (CSF), were measured in patients with various inflammatory neurological diseases and Parkinson's disease, and the following results were obtained. (1) In patients with neuro-sarcoidosis, neuro-Behçet's disease and meningitis, CSF T-N levels were markedly elevated in the exacerbation or acute stages of their neurological symptoms and remarkably decreased in the remission or chronic stages. In the neuro-sarcoidosis and neuro-Behçet's disease patients, however, CSF T-B levels showed no substantial change. (2) There was a significant positive correlation between CSF T-N levels and CSF/serum albumin ratios only in the meningitis patients. However, increases of CSF T-N levels were not associated with those of plasma T-N levels. (3) In the Parkinson's disease patients, CSF T-N levels remained normal, although CSF T-B levels significantly decreased. (4) A gradient for the CSF T-N value (lumbar greater than ventricular CSF), being reverse to the CSF T-B value, was observed. These results indicate that the significance of CSF T-N is quite different from CSF T-B, and that CSF T-N appears to be a valuable biochemical marker for evaluating the activity of inflammation within the central nervous system. Its measurement seems useful for therapeutic monitoring, especially of patients showing the chronic exacerbating-remitting course.

Juvenile parkinsonism: ventricular CSF biopterin levels and clinical features

Total biopterin (T-BP) levels in the ventricular cerebrospinal fluid (CSF) and clinical features of 19 patients with juvenile parkinsonism (JP: Parkinson's disease manifesting below the age of 40) were evaluated and compared with 61 patients with classical Parkinson's disease (classical PD: symptoms developing at the age of 40 or above). The JP patients were divided into two subgroups: JP-I; those with good response to levodopa followed by marked motor fluctuations and dopa-induced dyskinesias (DID), JP-II; those with milder response than JP-I with less fluctuations and DID being more similar to classical PD. Both of the mean ventricular CSF T-BP concentrations in the JP and classical PD patients were significantly lower than that in neurological controls. Moreover, the mean T-BP level in the JP-I was markedly lower than that in the JP-II or classical PD. Total biopterin levels revealed a gaussian distribution in the classical PD. However, a bimodal distribution was noted in the JP, with the lower peak consisting of only JP-I patients. These results seem to indicate that JP-II represents early-onset classical PD, while JP-I represents a distinct subgroup having a different physiopathology from classical PD.

Clinico-pathological correlations in Parkinson's disease

Based on comparative clinical and morphometric studies in 45 autopsy cases of Parkinson's disease (PD), 27 clinically presenting with akinesia and rigidity (AR-type), 18 with predominant resting tremor (T-type), the neurobiological basis of the major clinical subtypes in PD is discussed. The AR-type showed higher neuronal losses in locus coeruleus (LC) and in medial and lateral parts of substantia nigra (SNM, SNL), suggesting lesion patterns different from the T-type. More severe cell loss in the serotonergic dorsal raphe nucleus was observed in PD patients with depression than in non-depressed ones. Demented PD subjects showed higher cell loss in SNM than non-demented ones indicating dysfunction of the mesocortical dopamine system, and significantly more severe Alzheimer lesions in isocortex and hippocampus. These and other recent data from the literature indicate that some major clinical features of PD are related to lesions of distinct neuronal systems.