Natural course of pontocerebellar hypoplasia type 2A

INTRODUCTION

Pontocerebellar hypoplasia Type 2 (PCH2) is a rare autosomal recessive condition, defined on MRI by a small cerebellum and ventral pons. Clinical features are severe developmental delay, microcephaly and dyskinesia.Ninety percent carry a p.A307S mutation in the TSEN54-gene. Our aim was to describe the natural course including neurological and developmental features and other aspects of care in a homogeneous group of PCH2 patients all carrying the p.A307S mutation.

PATIENTS AND METHODS

Patients were recruited via the German patients' organizations. Inclusion criteria were imaging findings of PCH2 and a p.A307S mutation. Data were collected using medical reports and patient questionnaires discussed in a standardized telephone interview.

RESULTS

Thirty-three patients were included. When considering survival until age 11 years, 53% of children had died Weight, length and head circumference, mostly in the normal range at birth, became abnormal, especially head circumference (-5.58 SD at age 5 yrs). Neurologic symptoms: Choreathetosis was present in 88% (62% with pyramidal signs), 12% had pure spasticity. Epileptic seizures were manifest in 82%, status epilepticus in 39%. Non-epileptic dystonic attacks occurred in 33%. General symptoms: feeding difficulties were recorded in 100%, sleep disorder in 96%, apneas in 67% and recurrent infections in 52%; gastroesophageal reflux disease was diagnosed in 73%, 67% got percutaneous endoscopic gastrostomy and 36% a Nissen-fundoplication. Neurodevelopmental data: All children made progress, but on a low level: such as fixing and following with the eyes was seen in 76%, attempting to grasp objects (76%), moderate head control (73%), social smile (70%), rolling from prone to supine (58%), and sitting without support (9%). Ten percent lost achieved abilities on follow-up. The presence of prenatal symptoms did not correlate with outcome.

CONCLUSION

Phenotype of this genetically homogeneous group of PCH2 children was severe with reduced survival, but compatible with some developmental progress. Our data support the hypothesis of an early onset degeneration which thereafter stabilizes.

Glutamate receptor block in Lurcher mutant mice during ontogeny and its effect on hippocampal long-term potentiation

Basic evaluation of the effect of chronic NMDA glutamate receptor (NMDAR) blockade on the hippocampal long-term potentiation (LTP) was performed in an animal model of inborn olivo-cerebellar degeneration (Lurcher mutant mice, LMM). NMDA receptor antagonist MK-801 was administered to mice in the dose 0.2 mg/kg of body weight, daily during two periods of their ontogeny: D5-D26 and D91-D111. In the consecutive 15 days some behavioral characteristics were studied using special methods for physical activity testing. Then LTP was investigated in LMM and also in their healthy littermates which served as controls (wild-type, WT). LTP in animals pre-treated with MK-801 showed significant long-term suppression of NMDAR activity, in both WT and LMM despite certain small differences between them. Our results show that cerebellar pathology on one hand and a physical activity on the other hand can influence the LTP in hippocampal region. It can be concluded that the results support the ideas of close functional cooperation between the brain structures which are involved in mechanisms of learning and memory.

The effect of nitric oxide synthase inhibitors nitro-L-arginine and 7-nitroindazole on spatial learning and motor functions in Lurcher mutant and wild type mice

Nitric oxide (NO) is an intercellular messenger that, among other things, plays an important role in the nervous system as a gaseous neurotransmitter, modulating long-term potentiation (LTP) induction of synaptic transmission. LTP has been suggested to be the basis of memory formation. On the other hand NO also participates in excitotoxic processes which play an important role in many neuropathological states. The aim of this work was to observe the effect of two NO synthase (NOS) inhibitors (N omega-Nitro-L-arginine, NA; 7-nitroindazole, NI) on spontaneous behaviour, spatial learning and motor functions in Lurcher (+/Lc) and wild type (+/+) mice, derived from the B6CBA strain. Heterozygous Lurcher mutant mice represent a natural model of the olivocerebellar degeneration. They suffer from postnatal, practically total, extinction of cerebellar Purkinje cells (due to the excitotoxic apoptosis) and a partial decrease of granule cells and inferior olive neurons (ION) because of the lost target of their axons. +/+ animals are healthy littermates of +/Lc. NA is a nonselective NOS inhibitor which influences, except neuronal (n), also endothelial (e) NOS with an impact on blood pressure, NI is a selective nNOS inhibitor without any circulatory effect. The adult animals of both types (+/Lc; +/+) were influenced by acute administration of both inhibitors (25 mg/kg i.p. 30 min. before experiments) and newborns only by both acute and long-term administration of NI (1 month, starting from postnatal day 2, P2). Control solutions - saline or solvents of both NA and NI inhibitors--diluted 1M HCl and dimethyl sulfoxide (DMSO) respectively, were given at a relevant volume in the same way. The effect of both inhibitors and control solutions on motor functions was tested using four standard procedures (horizontal wire, slanting ladder, rotating cylinder, foot-bridge); in newborns at the age of 14 days. Spatial learning ability was examined in five-day long procedure in the Morris water maze (MWM) (in newborns started on P21). Spontaneous behaviour was studied only in adult animals (after acutely influencing them) employing the open field method. The results showed, that neither the Lurcher mutant, nor wild type mice derived from the B6CBA strain were significantly affected by NOS inhibitors NA and NI in spatial learning after both the acute and long-term application. Only significant decrease of swimming speed was found in both types of mice after the acute administration of NI and in the wild type animals after the acute administration of NA. Motor functions were significantly negatively affected only in the Lurcher mutants after both the acute and chronic application of NI.

Rhabdomyolysis in pontocerebellar hypoplasia type 2 (PCH-2)

Pontocerebellar hypoplasia type 2, an autosomal recessive neurodegeneration with prenatal onset, is characterised by progressive microcephaly and chorea/dystonia and has not previously been associated with muscular involvement. The gene associated with PCH-2 is unknown. An episode of rhabdomyolysis is reported in two non-related children with PCH-2, fatal in one, precipitated by intercurrent disease. Muscle biopsies in two other PCH-2 patients, and in one rhabdomyolysis patient whose biopsy antedated this complication showed areas of myofibrillar disruption or necrosis. Postmortem muscle sampled in another case without neuromuscular symptoms revealed focal necrosis, regenerating small fibres and upregulation of HLA-ABC. Random serum creatine kinase values in six other PCH-2 patients without clinical signs of neuromuscular involvement were increased in four. Collected data provide preliminary evidence of a subclinical myopathy associated with PCH-2.

[Study of brainstem auditory evoked potentials and its correlation with pontine volume in olivopontocerebellar atrophy]

AIM

To investigate the change of latency and interpeak latency of each component of BAEP (brainstem auditory evoked potential, BAEP) and its correlation with PV/PFV (pontine volume/posterior fossa volume, PV/PFV) ratio in OPCA (olivopontocerebellar atrophy, OPCA).

METHODS

We used Keypoint EMG/EP to determine waves I PL (peak latency, PL), III PL, V PL and I - III IPL (interpeak latency, IPL), III - V IPL, I - V IPL and used 1.5TMR 3D volume rendering software to determine PV (pontine volume, PV), CV(cerebellar volume, CV) and PFV (posterior fossa volume,PFV). Then calculated PV/PFV ratio, CV/PFV ratio and PV/ CV ratio in OPCA group and control group.

RESULTS

Compared with control group, in OPCA group wave IIII PL, I - III IPL were significantly elongated (P < 0.05), III - V IPL was significantly shorten (P < 0.05), PV/PFV ratio was significantly decreased (P < 0.01); there was a positive correlation between III-V IPL and PV/PFV ratio (r = 0.83, P < 0.01).

CONCLUSION

In patients with OPCA, III PL, I - III IPL of BAEP were elongated and III - V IPL of BAEP was shorten. III - V IPL became shorter when the volume of pontine decreased.

Topographic brain mapping of the international cooperative ataxia rating scale

The International Cooperative Ataxia Rating Scale (ICARS) is a 100-point semiquantitative scale designed primarily to assess cerebellar dysfunction. However, little is known of the metric properties of this scale. We assessed the ICARS by rating the severity of cerebellar dysfunction in 27 patients with spinocerebellar ataxias (SCA), three patients with sporadic olivopontocerebellar ataxia and 24 healthy control subjects. [(18)F]-fluorodeoxyglucose (FDG) positron emission tomography (PET) study was also performed on each subject. The statistical parametric mapping analyses revealed a significant correlation between the ICARS scores and functional impairment of the frontal regions within SCA patients. The glucose metabolism in the cerebellum, thalamus and caudate nucleus had significant differences between SCA patients and healthy control subjects. The results suggested that the clinical severity of SCA patients correlated with the functional impairment in the frontal regions, the targets of cerebellar efferent projections.

The time-dependent block of NMDA glutamate receptor influences hippocampal LTP in inborn cerebellar degeneration mouse model

The effect of single dose of NMDA glutamate receptor blockage administration on the hippocampal LTP was evaluated in animal model of inborn cerebellar degeneration. We compared the level of possible LTP blockade in two groups of animals, Lurcher mutant mice and their healthy littermates which served as controls. In the second part of the study we tested group of mice which were influenced repeatedly by the same NMDA blocker (MK-801) during behavioral experiments. Our results suggest a similar effect of blockade either after single or chronic MK-801 administration; both of them practically disrupted LTP generation with differences between healthy and neurodegenerative animals.

Motor and visuospatial abilities in a model of olivocerebellar and retinal degeneration--Lurcher mutant mice of C3H strain

Lurcher mutant mice represent a natural model of olivocerebellar degeneration. They suffer from loss of Purkinje cells and decreased number of granule cells and inferior olive neurons. The degeneration leads to cerebellar ataxia and deterioration of cognitive functions. Some animals of the C3H strain have also the retinal degeneration. The aim of the study was to analyze the morphology of cerebellar and retinal degeneration and to evaluate the ability of motor coordination and visuospatial orientation in C3H Lurcher mutant mice. Cerebella of Lurcher mutant and wild type mice were examined with several histological, histochemical and immunohistochemical methods. Motor coordination was tested on a bar, ladder and rotarod. Spatial orientation and learning were tested in the Morris water maze with visible or hidden platform. Histological examinations showed decreased numbers of Purkinje cell in Lurchers. Various histological methods brought different information about the course or stage of the cerebellar degeneration. Retinal degeneration was identified with hematoxyline-eosine staining very well. Lurchers performed worse in motor coordination tests and in both the spatial orientation and learning test. Retinal degeneration influenced negatively both the spatial learning and orientation. Motor tests were influenced by retinal degeneration only in the wild type mice. Wild type mice showed some ability of idiothetic navigation, which was not found in Lurchers.

Does transplantation of cerebellar embryonic tissue influence hippocampal LTP in adult Lurcher mutant mice?

Possible influence of embryonic cerebellar graft transplanted into the adult neurodegenerative brain in Lurcher mutant mice on long-term potentiation (LTP) in hippocampus was investigated. Evaluation of LTP ability and comparison with the tests of motor learning suggests similarities between magnitude of LTP and criteria of motor learning. Also interstrain differences were described. Our results support ideas about tight cooperation among brain structures which are involved in mechanisms of learning and memory.

Neural functional and morphological consequences of retinal degeneration in C3H Lurcher mutant and wild type mice

Lurcher mutant mice represent a model of olivocerebellar degeneration associated with the total functional elimination of the cerebellar cortex. The affected animals suffer from cerebellar ataxia and worsening of cognitive functions. Healthy littermates of Lurchers-wild type mice serve as controls. Except mentioned patterns some animals derived from the C3H strain exhibit signs of a hereditary retinal degeneration. The impact of the retinal degeneration on visuospatial abilities and on the neuronal morphology in visual projection of both C3H Lurcher mutant and wild type mice has been studied in this work. The Morrris water maze was used for examination of spatial learning when the animals learned to find a platform hidden under the water surface. Time of reaching the platform (escape latency) in individual experimental days as well as the swimming velocity was measured and the strategy of maze exploration was assessed. The presence of the retinal degeneration was proved histologically by means of classical hematoxillin-eosin method. The neurohistological examination of the superior colliculus and visual cortex was performed using a Ramón-Moliner modification of the Golgi method. The results obtained showed that retinal degeneration influenced the strategy of the maze exploration and caused generally worse results. The histological examination of eyes in animals with bad results confirmed presence of the retinal degeneration. The neurohistological examination of the brain visual projections of animals affected with the retinal defect showed most detectable changes in dendritic spines of the V1 cortex (lower density in general and less immature types).

Autonomic nervous evaluation in the early stages of olivopontocerebellar atrophy

The clinical significance of evaluating autonomic nervous system functions in the early stages of olivopontocerebellar atrophy (OPCA) has been investigated in 13 OPCA out-patients (7 males and 6 females, mean age: 51.0 years). We have employed measurements of blood pressure, plasma norepinephrine (NE), CVR-R, low-frequency power/high-frequency power ratio (L/H), high-frequency power (HF) score and heart rate (HR) monitoring using Holter ECG recording for evaluation of CVR-R. We have also carried out urodynamic examinations, focusing on the possible existence of bladder dysfunction. Although no significant changes were noted between control and OPCA groups concerning HR, CVR-R, L/H, plasma levels of norepinephrine and systolic blood pressure, HF (high-frequency power) (ms(2)), especially at night time, invariably showed a significant decline in OPCA groups. All OPCA patients who showed a decreased circadian HF also exhibited a tendency towards urinary bladder dysfunction. The present results appear to relate to disorder of the parasympathetic autonomic nervous system and neuromuscular dysfunction in the lower urinary tract. In conclusion, HRV (heart rate variability) analysis is a useful and safe tool and a keen predictor for evaluating functional states of autonomic nervous activity, especially in the early stages of OPCA. This study has also suggested the possible efficacy of urodynamic measurements in OPCA patients as an indicator of neuromuscular dysfunction in the lower urinary tract and of parasympathetic malfunction.

An autopsy case of early ("minimal change") olivopontocerebellar atrophy (multiple system atrophy-cerebellar)

We report a 57-year-old woman with multiple system atrophy (MSA) of 15-month duration. The patient developed dysarthria, followed by impaired balance of gait, mild limb ataxia, and saccadic eye movement. A postmortem examination performed after she was found dead in a bathtub revealed neuronal loss restricted to the olivopontocerebellar system, being more severe in the pontine nucleus. Mild neuronal loss was also found in the anterior vermis and inferior olivary nucleus. Alpha-synuclein immunohistochemistry demonstrated widespread occurrence of glial cytoplasmic inclusions in the central nervous system, which were more numerous in the pontine base and cerebellar white matter. In contrast, neuronal alpha-synuclein accumulation was confined to the pontine and inferior olivary nuclei. The number of neuronal intranuclear inclusions was much higher than that of neuronal cytoplasmic inclusions. Moreover, alpha-synuclein accumulation was more severe in the neurites than in the cytoplasm or nucleus. This case demonstrates the early pattern of brain pathology in MSA-cerebellar (olivopontocerebellar atrophy).

[Analysis of brain images in patients with spinocerebellar degeneration; using statistical parametric mapping (SPM) and easy Z score imaging system (eZIS)]

In order to investigate the cerebral blood flow objectively, the easy Z score imaging system (eZIS), was developed, and has been applied in clinical practice. SPECT with 99mTc-ethyl cysteinate dimer (99mTc-ECD) was performed, and the images were analyzed using the SPM97 and the eZIS Ver. 2 to investigate cerebral blood flow in patients with two types of spino-cerebellar degeneration. We compared the distribution of cerebral blood flow between 13 patients with cortical cerebellar atrophy (CCA) and 26 patients with olivopontocerebellar atrophy (OPCA). In the both groups, cerebellar blood flow was decreased generally. In our evaluation using the eZIS Z score, the scores for the brain stem and cerebellar nucleus in the OPCA group were lower than those in the CCA group. This method facilitates the objective evaluation of cerebral blood flow in patients with spinocerebellar degeneration, and may be useful for analyzing the condition of these disease.

[Spinal muscular atrophy associated with olivopontocerebellar hypoplasia. A case report]

INTRODUCTION

Spinal muscular atrophy is a frequent neurodegenerative disease in infancy. Nevertheless, its association with olivopontocerebellar hypoplasia is rare.

CASE REPORT

We describe a case displaying clinical symptoms that included respiratory failure, dysmorphias, hypotonia, deep tendon areflexia and respiratory complications, like the cases described in the literature. In the genetic study it was not possible to find the motor neuron gene surviving from the infantile muscular atrophy. The neuropathological disorders found in the necropsy study were olivopontocerebellar hypoplasia with intense neuronal loss (fundamentally from Purkinje cells and from the granular layer of the cerebellum, olivary nuclei and pons), replacement gliosis and degeneration of the motor cells in the anterior horn of the spinal cord. Death occurred due to a respiratory complication in the 11th postnatal month.

CONCLUSIONS

The paper describes the clinical-pathological study and the genetic study of a female patient who died at the age of 11 months after being diagnosed as presumably suffering from Werdnig-Hoffman disease. The autopsy revealed an olivopontocerebellar hypoplasia, which is a morphological trait that is not associated with the above-mentioned entity. The microscopic study revealed extensive areas of gliosis and neuronal loss. We conclude with the diagnosis of spinal muscular atrophy associated with olivopontocerebellar hypoplasia, which is a rare clinical entity with very few case reports and whose genetic defect is still unknown. We also review the extant literature related to this case.

Functional consequences of retinal degeneration in spatial orientation in C3H wild type and Lurcher mutant mice

Lurcher mutant mice represent a model of genetically determined olivocerebellar degeneration. In the C3H strain there is also hereditary retinal degeneration. The aim of this work was to assess, whether the retinal degeneration influences spatial orientation and results of the spatial learning tasks. Two experiments in the Morris water maze were arranged. First, mice learned to find a platform position, which was linked to two labels on the periphery of the maze. In the second experiment the platform was removed and swimming velocity and preference of central or peripheral zone of the maze were assessed. Presence of the retinal degeneration was detected histologically. Both Lurcher mutant and wild type mice that exhibited long latencies in the first experiment were affected with the retinal degeneration, while animals that performed the trial well, had normal retina. Swimming velocity was not changed substantially. The maze exploration strategy was different in mice with and without the retinal degeneration.

Effect of whole-body exposure to high-frequency electromagnetic field on the brain electrogeny in neurodefective and healthy mice

A direct registration of brain cortical and hippocampal activity during a high-frequency electromagnetic field (HF EMF) exposure was performed. All experimental procedures were done under urethane anaesthesia (20%, 2 g/kg i.p.) in Lurcher mutant mice, wild type (healthy littermates) were used as controls. Experimental animals were exposed to the HF EMF with frequency corresponding to cellular phones. Our method is based on the use of gel electrodes (silicon tubes or glass microcapillaries filled with agar) where the connection with classical electrodes is located out of HF EMF space. ECoG evaluation showed a distinct shift to lower frequency components but clear effect has been observed only in wild type (healthy) mice whereas in Lurcher mutant mice only gentle differences between frequency spectra were found. Measurement of hippocampal rhythmicity showed gentle changes with increase of higher frequencies (i.e. opposite effect than in cortex) and changes in theta oscillations registered from a dentate gyrus and CA1 area in both types of animals (healthy and mutant). These findings support the idea about possible influencing the central nervous system by HF EMF exposure and support also some recent results about possible health risks resulting from cellular phones use.

[Anesthetic management of a patient with olivopontocerebellar atrophy using heart rate variability (HRV)]

A 65-year-old woman with olivopontocerebellar atrophy (OPCA), manifested with cerebellar ataxia mainly, with coexisting impairment of the autonomic nervous system function, and extrapyramidal symptoms, was scheduled for cholecystectomy. With no premedication, anesthesia was induced with sevoflurane and maintained with 1-1.5% of sevoflurane and 66% of nitrous oxide mixed with oxygen. Heart rate variability (HRV) calculated from ECG was used for a monitor of the autonomic nervous system activity. Before the induction of anesthesia, severe reduction of the HRV parameters suggested that both her sympathetic and parasympathetic nervous activities might have been severely reduced. We considered that the patient might have postganglionic sympathetic nerve hypersensitivity against inotropic agents. When her blood pressure decreased temporarily after the induction of anesthesia, a bolus dose of ephedrine 1 mg wa given intravenously, which stimulated the sympathetic nervous system indirectly, and could increase her blood pressure. Hypotension during anesthesia in a patient with OPCA with severe autonomic nervous failure was successfully treated by a minimal dose of ephedrine.

Motor learning processes in a movement-scaling task in olivopontocerebellar atrophy and Parkinson's disease

Nine Parkinson's disease (PD), seven olivopontocerebellar atrophy (OPCA) patients and two age-matched control groups learned a linear arm movement-scaling task over 2 days, requiring movements proportional in length to visually presented target-bars. Scaling was acquired through knowledge of results (KR concerning the direction and magnitude of errors) following every second acquisition trial. Initial acquisition of both groups was significantly worse than their respective controls (poorer movement scaling), but rapidly improved to nearly identical levels. Retention for the PD group's movement scaling was as good as controls initially, but markedly poorer after 24 h. The OPCA group did not show this deficit. Both patient groups extrapolated accurately to longer, previously unpracticed target distances (no KR provided), suggesting an unimpaired capacity to generate and use an internal representation of the movement scaling. They also rapidly learned a new scaling relationship when the gain was changed. Overall, the learning of this movement-scaling task was not adversely affected in OPCA, and the impairment was restricted primarily to longer-term retention in PD. The study suggests that: (1) the ability to acquire movement scaling in a task that requires conscious use of error feedback and no new coordination may depend little on the cerebellum, and (2) the basal ganglia may participate in longer-term storage of scaling information.

Cutaneous sympathetic function in patients with multiple system atrophy

Some procedures increase the sweat output (SSwR; sympathetic sweat response) and reduce the cutaneous blood flow (SVR; skin vasomotor reflex) in the hand. We evaluated SSwRs and SVRs to deep inspiration, mental arithmetic, exercise, and tactile stimulation in 40 MSA patients and 15 healthy controls. We also conducted head-up tilt tests and R-R interval variation tests (CV(R-R)). SSwRs were present in all controls, but absent in 19 (47.5 %) of the MSA patients. The mean SSwR amplitudes in the MSA group were significantly lower than those in the control group. SVRs were evoked in all subjects except 3 MSA patients. There were no marked differences in SVR amplitudes between the two groups. Orthostatic hypotension and low CV(R-R) values were seen in 18 (45 %) and 13 (32.5 %) of the MSA patients, respectively. SSwR amplitudes correlated significantly with postural fall in blood pressure and CV(R-R) values in the MSA group. SSwRs were absent in about half of the MSA patients, and the SSwR results correlated with those of the cardiovascular autonomic tests. The SVRs were not severely disturbed in the MSA patients. We considered SSwR a useful index for the detection of autonomic dysfunction in MSA.

Exaggerated auditory startle responses in multiple system atrophy: a comparative study of parkinson and cerebellar subtypes

OBJECTIVE

Auditory startle responses (ASRs) have recently been reported to be exaggerated in cranial and peripheral nerve supplied muscles of patients with multiple system atrophy (MSA). ASRs displayed increased probability, amplitude and duration, shorter onset latency, and reduced habituation in comparison with healthy subjects. In order to investigate whether certain ASR features may differentiate MSA subtypes, the authors studied ASRs in 21 MSA patients (olivopontocerebellar type, MSA-C: n = 8, striatonigral type, MSA-P: n = 13), and 17 age-matched normal controls.

METHODS

ASRs were elicited by binaural high-intensity auditory stimuli which differed randomly in tonal frequency and intensity (250 Hz, 90 db; 500 Hz, 105 db; 750 Hz, 105 db; 1000 Hz, 110 db normal hearing level), presented through tubal insert phones. Reflex electromyographic activity was simultaneously recorded with surface electrodes from masseter, orbicularis oculi, sternocleidomastoid, biceps brachii, abductor pollicis brevis, rectus femoris, tibialis anterior, and soleus muscles.

RESULTS

Eighteen MSA patients (86%) had exaggerated ASRs as compared to normal subjects. At group level, indices of ASR disinhibition including increased ASR probability (in extremity muscles), shortened onset latency, and enlarged response magnitude were significantly more marked in MSA-P as compared to MSA-C patients. ASR probability showed habituation in normal subjects, less in MSA-P. and none in MSA-C patients. Three MSA-patients had no ASRs except in orbicularis oculi muscle.

CONCLUSIONS

Although absent ASRs may occur in some MSA patients, most of them exhibit exaggerated ASRs. This finding may reflect disinhibition of lower brainstem nuclei due to the degenerative disorder. ASRs were significantly more disinhibited in MSA-P versus MSA-C. suggesting involvement of different neural structures in the two MSA-subtypes.

Selective loss of expression of glutamate GluR2/R3 receptor subunits in cerebellar tissue from a patient with olivopontocerebellar atrophy

Expression of the mRNAs encoding the astrocytic (EAAT1, EAAT2) and neuronal (EAAT3, EAAT4) excitatory amino acid transporters and the AMPA-type glutamate receptor subunits GluR2 and GluR3 was investigated in postmortem cerebellar extracts from a patient with olivopontocerebellar atrophy (OPCA) and in material from three age-matched controls. Decreased expression in the steady state level of EAAT4 mRNA in the OPCA sample was correlated with the selective loss of Purkinje cells. Neuropathological evaluation revealed reactive gliosis and concomitantly increased expression of the mRNA encoding astrocytic glial fibrillary acidic protein (GFAP). Expression of the mRNAs encoding the AMPA receptor subunits GluR2 and GluR3 subunits was found to be decreased in OPCA suggesting that excitotoxic mechanism could play a role in the pathogenesis of the selective neuronal cell death in this disorder.

Pontocerebellar hypoplasia type 2: further clinical characterization and evidence of positive response of dyskinesia to levodopa

Pontocerebellar hypoplasia type 2 (PCH2) is a very rare autosomal recessive disorder. We report two unrelated female patients born to consanguineous parents presenting with this condition. Patient 1 showed a classical clinical/neuroradiological phenotype of PCH2 with dyskinesia/dystonia. Patient 2 had a neonatal onset of PCH2 with polyhydramnios, apneic spells, myoclonus, and an akinetic/rigidity condition. Neuroradiologically, patient 2 showed extensive pancerebral degeneration. Based on these observations, and in accordance with the published cases, two groups of PCH2 patients may be defined: (a) patients with dyskinesia/dystonia, severe hypoplasia of the infratentorial structures and less severe involvement of the supratentorial brain; and (b) patients with polyhydramnios, neonatal onset with tremulousness (hyperekplexia), no spontaneous activity, absence of dyskinesia and pancerebral degeneration. Finally, we report a dramatic positive response of the patient with dyskinesia/dystonia to levodopa treatment, and discuss the associated physiopathological implications.

[Man aged 49 years suffering from progressive clinical picture with palatal tremor, segmental myoclonus, ataxia, parkinsonism, amyotrophy, pyramidal signs, supranuclear ophthalmoplegia and cognitive decline]

In this clinicopathological conference we discuss the case of a patient aged 49 years, who developed progressive clinical picture characterized by palatal tremor (PT), segmental myoclonus, cerebellar ataxia, parkinsonism, amyotrophy, pyramidal signs, supranuclear ophthalmoplegia, parkinsonism and cognitive decline. He died 10 years after onset. There was no family history of ataxia. Initially a diagnosis of cerebral Whipple's disease was given, but prolonged treatment with ampicilin and cloramfenicol did not modify the clinical course. Magnetic resonance imaging study showed cerebellar and brainstem atrophy. Electrophysiological examination revealed neurogenic electromyographic pattern and abnormal somatosensory and brainstem evoked potentials. Starting from symptomatic PT, as the guide sign, a presumptive pathological diagnosis of sporadic olivopontocerebellar atrophy (OPCA) was established, probably of multiple system atrophy (MSA) type. Neuropathological study demonstrated OPCA with preferential involvement of cerebellum but without glial inclusions. This case illustrates the great clinicopathological complexity of OPCA and that not all forms of sporadic OPCA may be included within MSA.

Associations between a cerebellar motor dysfunction scale and movement initiation and completion in olivopontocerebellar atrophy

Correlations were drawn between subscores of a cerebellar motor dysfunction (CMD) scale and simple reaction time (RT) and movement time (MT) in patients diagnosed with olivopontocerebellar atrophy (OPCA). Poor performance on CMD subscores was correlated with long disease duration and lengthening of visual and auditory RT and MT, with the motor speed subscore showing the highest correlations. OPCA patients with severe cerebellar HMPAO uptake deficiency on single photon emission computed tomography scans had poorer performances on three of the four subscores (static equilibrium, dynamic equilibrium and nystagmus, and motor speed) than patients with mild deficiency. These results are discussed in terms of the role of cerebellar afferent/efferent pathways on different types of motor dysfunction in patients with cerebellar atrophy.

Cell death signaling in the cerebellum in Creutzfeldt-Jakob disease

Examination of the expression of proteins linked with signaling pathways commanding cell death and cell survival has been carried out to increase understanding on the mechanisms leading to cell death in the cerebellum in Creutzfeldt-Jakob disease (CJD). Expression of Fas, Fas ligand (Fas-L), ERK, MEK, Bcl-2, Bax, N-myc, c-myc, pro-caspase-2 and active caspase-3 was examined by immunohistochemistry in the cerebellum of six patients with sporadic CJD, three patients with olivopontocerebellar atrophy (OPCA) and six age-matched controls. No modifications in the expression of these proteins were observed in granule cells in CJD and OPCA when compared with controls, except in a few cells in the molecular and granular layers in CJD that displayed dense homogeneous active caspase-3 immunostaining. This suggests selective activation of caspase-3 in association with increased cellular vulnerability in CJD. No modifications in pro-caspase-2 and c-myc immunoreactivity were observed in Purkinje cells in diseased brains when compared with controls. However, increased diffuse Fas, Fas-L, MEK, ERK and Bax expression, and enhanced granular active caspase-3 immunoreactivity was found in the cytoplasm of Purkinje cells in CJD. Increase in Bcl-2 and N-myc occurred in Purkinje cells in CJD and OPCA. These results indicate that enhanced Fas, Fas-L, MERK, ERK, Bax and granular active caspase-3 expression is not lethal to Purkinje cells in CJD, whereas increased Bcl-2 and N-myc does not preclude per se cell death or death survival in CJD and OPCA. These findings point to the likelihood that expression of these cell death proteins in neurodegeneration has functional roles differing from those related with apoptosis.

Clinical effects of elastic bandage on neurogenic orthostatic hypotension

Neurogenic orthostatic hypotension (OH) often causes troublesome symptoms such as dizziness, syncope and falling, interfering active daily life or various therapies in rehabilitation. Nonpharmacologic measures for treating patients with OH include wearing elastic leotard, head-up tilting at night, etc. Elastic garment or antigravity suits is certainly effective, but it may be uncomfortable and not practical. Although elastic bandage (EB) bound on the lower limbs has been thought to be useful, there is few clinical report about its beneficial evidence. We investigated short-term clinical effects of commercially available EB on OH, and estimated the mechanism of its effectiveness by measuring some blood pressure-related humoral variables in neurodegenerative patients with OH.

Motor cortex excitability in patients with cerebellar degeneration

OBJECTIVES

To study motor cortex (M1) excitability and the effect of subthreshold transcranial magnetic stimulation (TMS) in patients with cerebellar degeneration and normals performing a reaction time (RT) task.

METHODS

Time to wrist flexion after a visual go-signal was measured. TMS was always delivered at 90% of resting motor evoked potential (MEP) threshold. In one experiment, test TMS was delivered at various intervals after the go-signal. In half the trials priming TMS was also given with the go-signal. A second experiment examined the effect on RT of M1 and occipital priming stimulation alone.

RESULTS

M1 excitability, measured as the likelihood of producing MEPs in the wrist flexor muscles, increased immediately after the go-signal in the patients and stayed high until movement. In controls, excitability rose gradually. This difference was largely eliminated by priming TMS. RT was longer in the patient group, but improved with priming TMS. Occipital priming produced less effect on RT than M1 stimulation in both controls (P=0.008) and patients (P=0.0004).

CONCLUSIONS

M1 excitability prior to movement in an RT task increases abnormally early in cerebellar patients. This may reflect compensation for deficient thalamocortical drive. Subthreshold TMS can partially normalize the prolonged RT and abnormal excitability rise in cerebellar patients.

Postural behaviour responses to visual stimulation in patients with vestibular disorders

Patients with different vestibular disorders exhibit changes in postural behaviour when they receive visual stimuli, reproducing environmental stimulation. Postural control was studied using an AMTI Accusway platform, measuring the confidential ellipse (CE) and sway velocity (SV). Postural responses were recorded according to the following stimulation paradigm: i) without specific stimuli; ii) smooth pursuit with pure sinusoids of 0.2 Hz (foveal stimulation); and iii) optokinetic stimulation (retinal stimuli). Patients with central vestibular disorders (CVD), cerebellar damage and unilateral peripheral vestibular lesions (UPVL) in asymptomatic periods were studied. A group of normal subjects was studied as control. Signal processing was done with a scalogram by wavelets in order to observe the relation between time and frequency in postural control. While patients with CVD and cerebellar disease showed a significant increase in CE and SV in the three conditions of the paradigm compared to the normal group, the patients with UPVL showed no change. Wavelets processing showed that the main sway occurs in the Y axis (antero-posterior) and below at 0.4 Hz in normal subjects, while the CVD and cerebellar patients showed sway frequencies in both the X and Y axes. The clinical implications of these findings are discussed.

Early onset cerebellar ataxia with retained tendon reflexes (EOCA) and olivopontocerebellar atrophy (OPCA): a computed tomographic study

Computed tomographic (CT) studies in olivopontocerebellar atrophies (OPCA) and 'early onset cerebellar ataxia with retained tendon reflexes (EOCA)' are few and vary widely in methodology and criteria for cerebellar and brainstem atrophy. In this prospective study, CT scan observations on 26 patients (EOCA-11, OPCA-15) were compared with 31 controls using qualitative and quantitative assessment of cisterns, ventricles and atrophy of brain. Vermian and/or cerebellar hemispheric (predominantly anterior) atrophy was present in 80.8% and both were equally common. Cerebral cortical atrophy (26.9%) and leukoariosis (15.4%) were less frequently seen. Statistically significant atrophy of pons, brachium pontis, cerebellum and midbrain was noted in patient group. No significant differences were observed between EOCA and OPCA groups. Evidence of atrophy did not correlate with either the duration of illness or the severity of cerebellar ataxia in both the groups. The severity of brainstem atrophy in 14 patients with and 12 patients without abnormal brainstem auditory evoked response did not differ significantly. This study highlights the methodology of CT evaluation for brainstem and cerebellar atrophy, draws attention to cerebral atrophy and emphasizes the lack of significant differences in CT morphology between OPCA and EOCA patients.

Effects of dopaminergic agents and of an NMDA receptor antagonist on motor coordination in Lurcher mutant mice

Lurcher mutant mice, characterized by an ataxic gait and olivocerebellar degeneration, were evaluated for motor coordination in the coat-hanger test after peripheral injections of two doses of dextromethorphan, a noncompetitive N-methyl-D-aspartate receptor antagonist, L-dopa/carbidopa, and SKF 77434, a dopamine D1 receptor agonist. There was an improvement in the distance traveled on the suspended horizontal string after 25 and 50 mg/kg of dextromethorphan and 37.5 mg/kg of L-dopa/carbidopa, but not after SKF 77434. None of the drugs reduced movement times or increased latencies before falling. These results indicate that NMDA receptor antagonism or stimulation of some dopaminergic mechanisms partially improve genetically determined cerebellar ataxia in mice.

Disappearance of rhythmic involuntary movements during sleep in a case of olivopontocerebellar atrophy

We report on a 54-year-old woman with an 8 or so year history of olivopontocerebellar atrophy associated with the rhythmic involuntary movements of the left upper and lower limbs, and cervical region. Surface electromyogram of the left upper limb revealed rhythmicity (about 3 Hz) and reciprocity between antagonistic muscles, which disappeared on polysomnography at all sleep stages including rapid eye movement sleep without atonia. These were characterized by the co-existence of rhythmic skeletal myoclonus and parkinsonian tremor. These findings suggest that a disturbance of the striatonigral system as well as the dentato-rubro-olivary circuit may be involved in these movements. It also seems that their fate is dependent on the level of wakefulness and that the ascending reticular activating system also plays a role in the development of these movements.

A case of nocturnal polyuria in olivopontocerebellar atrophy

We report a case of olivopontocerebellar atrophy without sleep apnea syndrome who presented nocturnal polyuria. It is considered that a disturbance in the circadian rhythm for arginine vasopressin secretion due to degeneration of suprachiasmatic nuclei and marked increase in the secretion of atrial natriuretic peptide due to abnormal diurnal variation in blood pressure may be involved in the mechanism of nocturnal polyuria.

Prolonged sympathetic reflex latency on skin nerves in sporadic cerebellar degeneration

BACKGROUND

Many physiological or pharmacological evaluations of autonomic function have been performed in patients with various types of cerebellar degeneration (CD). Few studies have been done, however, using neurographic recordings in patients with CD, especially of sudomotor or vasoconstrictor nerves.

OBJECTIVE

To confirm the clinical importance of sympathetic reflex latencies on the skin nerves of patients with various types of CD.

DESIGN AND SETTING

Case-comparison study at an academic center.

PARTICIPANTS

We studied 12 patients who had sporadic CD (cerebellar cortical atrophy, olivopontocerebellar atrophy, and Shy-Drager syndrome) and 15 healthy volunteers as controls.

METHODS

Skin sympathetic nerve activity (SSNA), sympathetic skin response, and skin vasomotor reflex were simultaneously recorded using randomly administered electrical stimuli.

RESULTS

In controls, SSNA reflex latency ranged from 640 to 864 milliseconds. Patients with cerebellar cortical atrophy exhibited slight but significant (P<.01) prolongation of reflex latency to the onset of reflex bursts. In patients with olivopontocerebellar atrophy, latency to the onset and the peak of reflex bursts was significantly prolonged (P<.001). Patients with Shy-Drager syndrome had no SSNA, sympathetic skin response, or skin vasomotor reflex, even with supramaximal electrical stimuli.

CONCLUSIONS

Prolonged reflex latency or the absence of reflex bursts on SSNA can be observed in patients with CD with various forms of autonomic dysfunction. The measurement of SSNA reflex latency may be a useful method of evaluating sympathetic function, including the central pathway.

[Urinary disturbance in olivopontocerebellar atrophy (OPCA)--changes during the progression of the disease]

PURPOSE

Among spinocerebellar degeneration, syndromes categorized as multiple system atrophy (MSA) are commonly associated with neurogenic bladder, and urinary disturbances change with the disease progression. Accordingly, the changes in the urodynamic findings during the progression of the disease have been studied in the case of Olivopontocerebellar atrophy (OPCA) and OPCA type of MSA.

METHODS

Urodynamic study (UDS) was performed more than twice in eight patients (5 males, 3 females, age 48-76, mean 55.0). The interval range between the first examination and follow up examination was 9-93 months (mean 42.4). UDS included cystogram, intravenous pyelography, residual urine volume, cystometry, urethral pressure profilometry, and external sphincter electromyography.

RESULTS

The bladder was deformed in almost all patients with the progression of the disease, but the upper urinary tract was properly preserved. Residual urine volume tended to increase, and residual urine rate worsened significantly. The stable detrusor activity seemed to become overactive accompanied by detorusor hyperreflexia, and finally seemed to be acontractile. The normal sphincter activity seemed to become overactive accompanied by detrusor-sphincter dyssynergia, and finally complete relaxation could't be observed.

CONCLUSION

These results suggest that urinary disturbance deteriorates together with other neuropathies as the disease progresses in OPCA. These patients should be continuously observed along with proper urinary management depending on the disease progression.

Vecuronium dose requirement and pupillary response in a patient with olivopontocerebellar atrophy (OPCA)

PURPOSE

Olivopontocerebellar atrophy (OPCA), a variant of spinocerebellar degeneration (Shy-Drager syndrome), is a systemic degenerative disorder affecting the neurons of multiple nuclei. We investigated the sensitivity to vecuronium and the pupillary responses to various stresses in a patient with OPCA.

CLINICAL FEATURES

A 65-yr-old woman with a six-month history of OPCA underwent a left upper lobectomy for lung cancer under propofol-N2O anaesthesia. She had symptoms of dysarthria, bulbar palsy, cerebellar ataxia, Parkinsonism, myosis, pyramidal signs and muscular atrophy of the distal extremities. A cumulative dose-response curve for vecuronium was constructed, and pupillary changes in response to various noxious stimuli were evaluated with concomitant recording of the Spectral-Edge-Frequency 90% (SEF90; the frequency below which 90 percent of the EEG power is located). The dose-response curve for vecuronium and the estimated ED50 value (the 50% blocking dose of vecuronium) in this patient with OPCA were almost identical with those of five ASA I-II patients (27 micrograms.kg-1 vs 31 micrograms.kg-1). The pupil size and the SEF90 did not change after tracheal intubation or surgical stimulation in this patient, while in the control subjects (n = 3), these measures increased in response to both stresses.

CONCLUSIONS

The absence of pupillary and SEF90 responses to noxious stimuli suggests a sensitivity to propofol and/or central autonomic dysfunction in patients with OPCA. Although the dose requirement of vecuronium in this patient was similar to that of the control patients, the effects of neuromuscular blockers may vary depending on the severity of muscle atrophy.

[Morphologic and functional characteristics of an animal model of cerebellar degeneration (lurcher mutant mice)]

Lurcher mutant mice are characterized by genetically determined degeneration of cerebellar Purkinje cells, granule cells and inferior olivary neurons (ION). In the morphological part of this study Lurcher mutant and wild type mice were given intraperitoneal injections of 3-acetylpyridine (3AP) to look at the effect of this neurotoxin and niacinamide antagonist on the ION. Intraperitoneal administration of 3AP is characterized by the different sensitivity of ION in Lurcher mutant mice and wild type mice in both infant and young adult animals. Lurcher mutants suffered a destruction of these neurons while wild type mice were unaffected. Since the cerebellum plays an essential role in the sphere of motor learning and behavior, in the functional part of this study we investigated some characteristics of early learning in Lurcher mutant and wild type mice. The first experimental results show some differences in the inhibitory reaction of the passive avoidance between Lurcher mutant and wild type mice in early ontogeny, during the first month of their life. Both morphological and functional findings show not only different effects of 3AP on genetically mutated and wild type mice in the same inbred strain but also some functional changes in the sphere of early learning and memory as well.

The hereditary ataxias

Efforts to classify the hereditary ataxias by their clinical and neuropathological phenotypes are troubled by excessive heterogeneity. Linkage analysis opened the door to a new approach with the methods of molecular biology. The classic form of autosomal recessive ataxia, Friedreich's ataxia (FA), is now known to be due to an intronic expansion of a guanine-adenine-adenine (GAA)-trinucleotide repeat. The autosomal dominant ataxias such as olivopontocerebellar atrophy (OPCA), familial cortical cerebellar atrophy (FCCA), and Machado-Joseph disease (MJD) have been renamed the spinocerebellar ataxias (SCA). Specific gene loci are indicated as SCA-1, SCA-2, SCA-3, SCA-4, SCA-5, SCA-6, and SCA-7. In 5 of them (SCA-1, SCA-2, SCA-3, SCA-6, and SCA-7), expanded cytosine-adenine-guanine (CAG)-trinucleotide repeats and their abnormal gene products cause the ataxic condition. The most common underlying loci for olivopontocerebellar atrophy (OPCA) are SCA-1 and SCA-2, although other genotypes may be added in the future. A major recent advance was the identification of the gene for SCA-3 and MJD, and the high prevalence of this form of autosomal dominant ataxia. In FA and the SCA with expanded CAG-trinucleotide repeats, clinical and neuropathological severity are inversely correlated with the lengths of the repeats. Anticipation in the dominant ataxias can now be explained by lengthening of the repeats in successive generations. Progress is being made in the understanding of the pathogenesis of FA and SCA as the absent or mutated gene products are studied by immunocytochemistry in human and transgenic murine brain tissue. In FA, frataxin is diminished or absent, and an excess of mitochondrial iron may cause the illness of the nervous system and the heart. In SCA-3, abnormal ataxin-3 is aggregated in neuronal nuclei, and in SCA-6, a mutated alpha1A-calcium channel protein is the likely cause of abnormal calcium channel function in Purkinje cells and in the death of these neurons.

Masseter reflex potentials in olivo-ponto-cerebellar atrophy

We recorded masseter reflex potentials to examine the correlation between the masseter reflex and the muscle stretch reflexes of limbs in 19 patients with olivo-ponto-cerebellar atrophy (OPCA). The patients were subdivided into hyper- (n = 5), normo- (n = 7) and hypo- (n = 7) reflexia groups according to the degrees of the conventional deep tendon jerks in the upper limbs. The masseter reflex potentials, elicited by tapping the chin with a reflex hammer, were recorded from the bilateral masseters using a pair of surface electrodes. The latency of the potentials in the hyporeflexia was significantly longer than in the other groups, while the amplitude of those in the hyperreflexia group was significantly higher than in the other groups. These results indicate that in patients with OPCA the magnitude and latency of the masseter reflex correlates with the status of the muscle stretch reflexes of the limbs in contrast with Friedreich's ataxia where the masseter reflex has been reported to be normal or hyperactive despite hyporeflexia in the limbs.

Neurobehavioral dimensions of olivopontocerebellar atrophy

Twenty-one patients with olivopontocerebellar atrophy (OPCA) and 21 normal controls of equivalent age, gender, and educational levels underwent a series of neurobehavioral tests thought to measure frontal lobe and parietal lobe functions as well as information processing speed. The patients with OPCA had higher reaction times and movement times, confirming the results of previous experiments. They had lower scores for some tests thought to be sensitive to dysfunction of the frontal lobe, such as hand sequencing, verbal reasoning, and proverb interpretation. Deficits in copying a simple figure and in immediate visual-spatial memory, thought to be indicative of parietal lobe dysfunction, were also discerned. These results are consistent with the hypothesis that the cerebellum is involved in visual-spatial working memory that requires rapid information processing, and that it modulates parietal lobe- and frontal lobe-mediated functions.

Non-familial olivopontocerebellar atrophy combined with late onset Alzheimer's disease: a clinico-pathological case report

A 76-year-old woman with olivopontocerebellar atrophy (OPCA) presented with progressive intellectual deterioration. She showed cerebellar ataxia and muscle atrophy and weakness, and gradually developed generalized dementia with visuospatial disturbance. An autopsy revealed numerous senile plaques (SPs), neurofibrillary tangles (NFTs) and neuropil threads particularly in the CA1, subiculum and entorhinal cortex and to a lesser degree in the cerebral neocortex shown by immunostaining and specific silver impregnation techniques. The nucleus basalis of Meynert had numerous NFTs with fibrillary gliosis and neuronal cell loss. The basis pontis was markedly atrophied and the pontine nucleus had severe neuronal depopulation and gliosis. The pontine transverse fibers were demyelinated with their axons being fragmented. The cerebellar white matter was also severely degenerated. The striatum, Onuf's and intermediolateral nuclei of the spinal cord remained unchanged. Ubiquitin immunohistochemistry and Gallyas silver impregnation technique revealed oligodendroglial inclusions in the pontine nucleus, corticopontine tract, cerebral and cerebellar white matter. On double immunostaining of KP1 and ubiquitin, globular neurite SPs encircled by KP1-positive fibrous structures were found in the hippocampus and cerebral neocortex. The curly neurite SPs contained KP1-positive granules. The KP1-positive microglial cells were distributed widely in the cerebral white matter and HLA-DR-positive ones were found around the SPs. The present case showed generalized dementia compatible with Alzheimer's disease (AD) and had a pathologically limbic type of late onset AD. This is the first case where AD affected non-familial OPCA.

[Olivopontocerebellar atrophy--a heterogenous morphologic syndrome]

Among the neuropathologically defined spinocerebellar degenerations, olivopontocerebellar atrophy (OPCA) represents a morphologic syndrome underlying different clinical, genetic, and biochemical conditions. Clinical and genetic classification systems include OPCA in sporadic cerebellar ataxias such as multiple system atrophy as well as in different autosomal recessive, autosomal dominant and X-chromosomal recessive cerebellar ataxias. According to findings of the last two decades, the historically derived term OPCA should be avoided in clinical use and should be regarded as a diagnostic contribution. A proper diagnostic classification of individual cases, however, has to consider all neuropathological, clinical and genetic data.

P300 and cerebral blood flow before and after TRH in olivopontocerebellar atrophy

Ten cases of olivopontocerebellar atrophy (OPCA) (mean age 56 +/- 9 years) and 8 healthy controls (mean age 58 +/- 9 years) were studied. The P300 was measured with a Synax 1100 evoked potential recorder and the regional cerebral blood flow was measured using the stable xenon computed tomography method. The P300 latency was significantly longer in the OPCA group than in the healthy control group. The P300 latency after the intravenous infusion of thyrotropin releasing hormone (TRH) in the OPCA group was significantly shorter than that before the intravenous infusion of TRH. The blood flows in all the measured areas (the cerebellar cortex, the cerebellar white matter, the brainstem, the thalamus, the basal ganglia, the frontal lobe cortex and the frontal lobe white matter) were significantly lower in the OPCA group than in the healthy control group. The blood flows in the cerebellar cortex and in the frontal lobe cortex after the intravenous infusion of TRH were significantly higher than those before the intravenous infusion of TRH. The prolongation of P300 latency in the OPCA group suggests that subclinical disturbance in recognition function is present in OPCA and may be related to the blood flow decrease outside the cerebellum.

Analysis of single-joint rapid movements in patients with sporadic olivopontocerebellar atrophy

Patients with pure cerebellar cortical atrophy (CCA) present isolated cerebellar signs, whereas patients with sporadic olivopontocerebellar atrophy (sOPCA) present various combinations of cerebellar and extracerebellar signs. However, the differential diagnosis between these two forms of cerebellar degeneration is often a challenge for the clinician. Therefore, any test helping in this differential diagnosis might have a potential clinical interest. In this study, our goal was to investigate the adaptation to increased inertia in patients with sOPCA exhibiting combined cerebellar and pyramidal signs, during the performance of fast wrist flexions. We found that these patients exhibited a hypermetria which remained unchanged after addition of inertia, because they were unable to increase neither their agonist activity (launching force), nor their antagonist activity (braking force). This contrasts with our previous findings in patients with CCA. In these latter, the hypermetria worsened when the inertial load of the hand increased because those patients were able to increase their agonist activity, but not their antagonist activity. The adaptation to inertia might thus help to differentiate CCA and sOPCA.

Movement-related cortical potentials and contingent negative variation in olivopontocerebellar atrophy

Movement-related cortical potentials (MRCPs) and contingent negative variation (CNV) were recorded in 8 cases of olivopontocerebellar atrophy (OPCA) and 8 age-matched healthy controls. The amplitude of the negative slope (NS') was smaller in the OPCA group than in the healthy control group. The amplitude of late CNV was smaller in OPCA group than in the healthy control group. These abnormalities in MRCPs and CNV were improved by intravenous infusion of thyrotropin releasing hormone.

Cardiovascular and renin responses to head-up tilt tests in parkinsonism

OBJECTIVES

We investigated cardiovascular and renin responses to head-up tilt tests in patients with Parkinson's disease (PD), multiple system atrophy (MSA), and in controls to determine variables for the assignment of parkinsonism to the potential underlying neurologic condition.

PATIENTS AND METHODS

Sequential changes in sympathetic-mediated circulatory variables such as heart rate, blood pressure, and plasma renin concentration during head-up tilt tests were studied in 14 patients with PD and 11 patients with MSA. Twelve subjects with normal autonomic functions were studied as controls.

RESULTS

Head-up tilt resulted in significant differences in blood pressure and heart rate responses between PD, MSA, and controls. The baseline plasma renin concentration was significantly lower in MSA than in controls. Twenty min head-up tilt revealed significant differences in plasma renin concentration between PD, MSA, and controls.

CONCLUSION

We conclude that investigating sequential changes in mean arterial blood pressure, heart rate, and plasma renin concentration during head-up tilt test can potentially support differential diagnosis of PD and MSA.

[Olivo-ponto-cerebellous degeneration. A study of 21 patients defined by the Quinn criteria]

21 patients with diagnosis of idiopathic OPCA were examined clinically and evaluated by MRI or CT-scan. On the basis of Quinn's criteria for MSA, patients were subdivided into those with probable MSA (48 p. cent) and those with possible MSA (52 p. cent). Median age at onset was 51.8 years. The initial clinical feature of the disease was ataxia, but the presence of multiple system involvement was clear in all cases. The combination of involvement of four different system (cerebellar, parkinsonian, pyramidal, autonomic) was the most common (28.5 p. cent), followed by the association of cerebellar and pyramidal features (24 p. cent). Autonomic symptoms were present in 48 p. cent of patients. CY-scan or MRI showed cerebellar and brainstem atrophy in 43 p. cent of cases. There was no relation with the duration of the disease or the severity of clinical features. Moreover brainstem auditory evoked response and EMG were not helpful in diagnosis.