Anticholinergic-responsive gait freezing in a patient with pantothenate kinase-associated neurodegeneration

A 43-year-old male patient suddenly developed freezing of gait (FOG) when making a first step, turning, or passing through a narrow path. Dystonic plantar flexion of his left foot always accompanied with FOG. He could walk without FOG when stepping on visual cues. Brain magnetic resonance imaging study showed typical "eye of the tiger" sign in the globus pallidus. He had heterozygous mutations in the exons 3 and 4 in the PANK2 gene. His FOG dramatically responded to the anticholinergic treatment. We report the first instance of a patient with genetically confirmed pantothenate kinase associated neurodegeneration showing typical FOG that responded to anticholinergic treatment.

Effects of disease duration on the clinical features and brain glucose metabolism in patients with mixed type multiple system atrophy

To study the effect of disease duration on the clinical, neuropsychological and [(18)F]-deoxyglucose (FDG) PET findings in patients with mixed type multiple system atrophy (MSA), this study included 16 controls and 37 mixed-type MSA patients with a shorter than a 3-year history of cerebellar or parkinsonian symptoms. We classified the patients into three groups according to the duration of parkinsonian or cerebellar symptoms (Group I = <or=1 year; II = 13-24 months; III = 25-36 months). We performed UPDRS, international cooperative ataxia rating scale (ICARS), and a neuropsychological test battery. We compared the FDG PET findings of each group of patients with controls. Group I patients frequently had memory and frontal executive dysfunction. They showed hypometabolism in the frontal cortex, anterior cerebellar hemisphere and vermis. They had parkinsonian motor deficits, but no basal ganglia hypometabolism. Group II and III patients frequently had multiple domain cognitive impairments, and showed hypometabolism in the frontal and parieto-temporal cortices. Hypometabolism of the bilateral caudate and the left posterolateral putamen was observed in Group II, and whole striatum in Group III. In summary, the cortical hypometabolism begins in the frontal cortex and spreads to the parieto-temporal cortex in MSA. This spreading pattern coincides with the progressive cognitive decline. Early caudate hypometabolism may also contribute to the cognitive impairment. Parkinsonian motor deficits precede putaminal hypometabolism that begins in its posterolateral part. Cerebellar hypometabolism occurs early in the clinical courses and seems to be a relevant metabolic descriptor of cerebellar deficits.

Moyamoya disease presenting with paroxysmal exercise-induced dyskinesia

We report a patient with moyamoya disease presenting with paroxysmal exercise-induced dyskinesia (PED). A 31-year-old lathe man developed recurrent attacks of paroxysmal hemichorea. The attacks always affected his left limbs and occurred either after several hours of working or while playing football. The duration of attacks ranged from 30 min to 4h. Attacks were not provoked by sudden movements, consumption of coffee or alcohol, hyperventilation, emotional stress, exposure to cold or passive movement. An MRI of the brain showed no parenchymal lesions. However, (99m)Tc-ethylcysteine dimer SPECT study showed hypoperfusion in the right striatum. Digital subtraction angiography showed stenosis of the right internal carotid and middle cerebral artery with prominent basal collaterals, which was compatible with moyamoya disease. Imaging studies of the cerebral arteries should be done in patients with clinical features of PED in order to detect possible cases of moyamoya disease.

Different cerebral cortical areas influence the effect of subthalamic nucleus stimulation on parkinsonian motor deficits and freezing of gait

Inconsistent response in freezing of gait (FOG) with levodopa treatment or STN DBS makes the pathogenesis difficult to understand. We studied brain areas associated with the expression of STN DBS effect on parkinsonian motor deficits and FOG. Ten Parkinson's disease patients with typical FOG were included. One month before STN DBS, we performed [(18)F]-deoxyglucose PET scans and measured the UPDRS motor and modified FOG (mFOG) scores during levodopa off and on periods. At two months after STN DBS, same rating scores were measured. The percentage improvement of mFOG and UPDRS motor scores by STN DBS during levodopa off period was calculated. We searched for brain areas in which glucose metabolism correlated with the improvement of mFOG and UPDRS motor scores by DBS. During levodopa off period, STN DBS improved the UPDRS motor scores by 32.3% and the mFOG scores by 56.6%. There was no correlation between the improvements of both scores. The improvement of UPDRS motor score by DBS correlated with the metabolic activities of rostral supplementary motor area (Brodmann's area 8; BA8), anterior cingulate cortex (BA32), and prefrontal cortex (BA9). On the other hand, there was a positive correlation between the improvement of mFOG score by DBS and the metabolic activity of the parietal, occipital, and temporal sensory association cortices. In conclusion, dysfunction of different cerebral cortical areas limits the beneficial effects of DBS on parkinsonian motor deficits and FOG.

Corticospinal disinhibition in paroxysmal kinesigenic dyskinesia

OBJECTIVE

To investigate the underlying mechanism responsible for paroxysmal kinesigenic dyskinesia (PKD).

METHODS

We performed a transcranial magnetic stimulation (TMS) study in 12 drug-naïve patients with PKD and 10 healthy volunteers. TMS parameters included resting motor threshold, recruitment curve of motor evoked potential amplitudes, short intracortical inhibition and facilitation, long intracortical inhibition (LICI), and silent period. We also measured compound muscle action potential.

RESULTS

LICI, representing GABA-mediated inhibition, was significantly reduced in the patients (P = 0.033), while results for all other TMS parameters tested were comparable between the two groups.

CONCLUSIONS AND SIGNIFICANCE

These results suggest that a specific type of corticospinal inhibitory mechanism is impaired in patients with PKD.

Genotypes of catechol-O-methyltransferase and response to levodopa treatment in patients with Parkinson's disease

A single nucleotide polymorphism at the nucleotide 1947 in the catechol-O-methyltransferase (COMT) gene encodes the high and low activity forms of the enzyme. We investigated COMT genotypes of 73 Korean patients with Parkinson's disease (PD), 29 with multiple system atrophy (MSA), and 49 controls, and analyzed the response to levodopa challenge in the PD patients. We found no significant difference in the distribution of the COMT genotypes among the three groups. The frequencies of the G- and A-alleles in the total population were 75 and 25%, respectively. The levodopa response was determined by a single oral levodopa challenge test with Sinemet (25/250 mg) in the patients with PD. The motor response evaluated by the time to peak response, the duration and magnitude of the response in the motor part of the Unified Parkinson's Disease Rating Scale; tapping or walking times showed no significant difference between the genotypes. Thus, pharmacokinetic or pharmacodynamic factors other than the investigated genetic variant of the COMT enzyme seem to determine the response to levodopa in PD.

Clinical and anatomical factors associated with thalamic dyskinesias

To define the clinical and anatomical factors associated with dyskinesias following thalamic infarction, we performed neurological examination and three-dimensional brain magnetic resonance imaging for 23 patients with thalamic infarction. We measured the total volumes and the largest diameters of the lesions on axial and coronal images. Using the atlas of human thalamus, we investigated the damaged thalamic nuclei. We compared the means of the volumes and the largest diameters of the lesions, and the frequencies of damaged thalamic nuclei between patients with and without thalamic dyskinesias. Seven (two pseudochoreoathetosis and five dystonia) of the 23 patients with thalamic infarction developed dyskinesias. No specific neurological deficits at the onset of stroke predicted the development of dyskinesias. The mean volume of the lesions of patients with dyskinesias (739 mm(3)) was significantly larger than that of those without dyskiensias (92.9 mm(3)). The means of the largest axial (11.6 mm) and coronal (10.8 mm) diameters were significantly larger in patients with dyskinesias, compared to those (axial, 7.1 mm; coronal, 6.4 mm) of patients without dyskinesias. Patients with dyskinesias had damage in the centromedian (CM) thalamic nucleus more frequently compared to those without dyskinesias. Patients with a large thalamic infarction involving the CM nucleus are more likely to develop dyskinesias.

Hemidystonia and hemichoreoathetosis as an initial manifestation of moyamoya disease

OBJECTIVE

To describe hemidystonia and hemichoreoathetosis in an adult patient with moyamoya disease without a previous history of cerebrovascular accident.

DESIGN

Case report.

SETTING

Tertiary care center.

PATIENT

A 22-year-old woman suddenly developed dystonic spasms in her left hand and left foot after a severe emotional stress. The dyskinesia gradually subsided over the next 4 months. Five months after the onset, she suddenly developed choreoathetoid movement in her right hand and right foot.

MAIN OUTCOME AND RESULTS

The patient had both somatic and cortical sensory deficits in the right hand and right foot. Magnetic resonance imaging of the brain showed an infarction at the right putamen and lesions involving the right frontal lobe and the left frontotemporoparietal lobe. Magnetic resonance cerebral angiography showed severe stenoses of both internal carotid arteries at the supraclinoid portion and numerous collateral vessels, compatible with moyamoya disease. Single photon emission tomography of the brain showed hypoperfused areas at the right frontal and left frontotemporoparietal lobes. The choreoathetosis of the right limbs improved markedly, along with improvement of sensory deficits.

CONCLUSIONS

To our knowledge, this is the first report of an adult patient presenting with hemidystonia and hemichoreoathetosis as the initial manifestations of moyamoya disease. Arch Neurol. 2000;57:1510-1512

Reciprocal inhibition between the forearm muscles in patients with paroxysmal kinesigenic dyskinesia

We measured the changes of forearm flexor H reflexes produced by conditioning radial nerve stimulation at delays of -2, 0, 2, 4, 7.5, 10, 25 and 75 ms in 10 patients with PKD and six with generalized seizure disorder. We compared the results with 12 normal volunteers. In the patients with PKD, we compared the amounts of reciprocal inhibition between the severely and the asymptomatic or mildly affected sides of arms. Follow-up studies were done in eight PKD patients after they responded to the anticonvulsant treatment. At each delay, patients with seizure disorders showed comparable amounts of changes with controls. Patients with PKD showed paradoxical facilitation at a delay of 0 ms, enhanced facilitation between 2 to 7.5 ms delays and attenuated inhibition at a delay of 75 ms. There were no significant differences in the amount of reciprocal inhibition according to the severity of clinical symptoms. Follow-up studies showed no significant changes of reciprocal inhibition compared to the baseline data. In PKD, paradoxical facilitation and enhanced first relative facilitation period may be caused by defective spinal interneurons. In addition to the defective reciprocal inhibition, abnormalities of supraspinal inputs seem to be involved in the genesis of PKD.