The effect of subthalamic nucleus stimulation on kinaesthesia in Parkinson's disease.

BACKGROUND: Parkinson's disease is accompanied by deficits in passive motion and limb position sense. OBJECTIVE: To investigate whether deep brain stimulation of the subthalamic nucleus (STN-DBS) reverses these proprioceptive deficits. METHODS AND RESULTS: A passive movement task was applied to nine patients with Parkinson's disease and bilateral chronic STN-DBS and to seven controls. Thresholds for 75% correct responses were 0.9 degrees for controls, 2.5 degrees for Parkinson's disease patients when stimulation was OFF, and 2.0 degrees when stimulation was ON. CONCLUSIONS: STN-DBS improves kinaesthesic deficits in Parkinson's disease, but does not lead to a full recovery of proprioceptive function.

POEMS syndrome in a 24-year-old man associated with vitamin B12 deficiency and a solitary lytic bone lesion.

We report one of the youngest cases of POEMS syndrome (polyneuropathy, organomegaly, endocrinopathy, monoclonal gammopathy, and skin changes), presenting in a 24-year-old man. A solitary lytic bone lesion and vitamin B12 deficiency were also found. We suggest that this syndrome be considered in cases of subacute polyneuropathy developing in young adults.

Atypical dopa responsive parkinsonism in a patient with megalencephaly, midbrain Lewy body disease, and some pathological features of Hallervorden-Spatz disease.

A 38 year old patient with megalencephaly, mental retardation, and lifelong tremor developed levodopa responsive parkinsonism in his mid-30s followed by the appearance of dyskinesiae, motor fluctuations, hallucinations, and dementia. Brain MRI showed, as well as other changes, iron deposition in the globus pallidus, substantia nigra, and the pulvinar of the thalamus. Postmortem examination disclosed depigmentation of the substantia nigra pars compacta with neuronal loss, gliosis, and Lewy body formation. Axonal dystrophic spheroids, neuronal loss, calcification, and iron deposition were found in the substantia nigra pars reticulata. Less severe changes without neuronal loss were seen in the globus pallidus. This combination of megalencephaly with neuroaxonal changes predominantly in the pars reticulata and Lewy body degeneration isolated to the substantia nigra pars compacta has not been previously reported.

Dopa-responsive parkinsonism phenotype of Machado-Joseph disease: confirmation of 14q CAG expansion.

The subtype IV of Machado-Joseph disease (MJD), characterized by parkinsonism variably combined with ataxia, distal atrophy, and sensory loss, has been all but ignored in recent reports of MJD, including those describing the molecular biologic substrate of the disease. We have demonstrated expansion of the CAG trinucleotide repeat of the MJD1 gene located on chromosome 14q32.1 in 2 patients of Azorean descent who presented with levodopa-responsive atypical parkinsonism. Previous publications have documented the presence of this expanded repeat in the other more common MJD phenotypes (I-III). To our knowledge, this is the first molecular biologic confirmation of the presence of the MJD1 gene in the subtype IV phenotype. Patients presenting with parkinsonism and peripheral neuropathy should be screened for this genetic defect.

Reversible cortical blindness (Anton's syndrome) associated with bilateral occipital EEG abnormalities.

A 50-year-old woman with systemic lupus erythematosus was admitted in an obtunded state. An EEG recorded while she was unconscious demonstrated one episode of rhythmic sharp wave activity in the left occipital area that lasted for 5 minutes and was followed later in the same recording by an episode of high amplitude sharp wave discharges in the right posterior temporal and occipital areas. When the patient regained consciousness, she had an Anton's syndrome of cortical blindness with denial. When she recovered light perception only, the EEG demonstrated synchronous and independent right and left occipital-posterior temporal periodic lateralized epileptiform discharges (PLEDs). Cortical blindness (Anton's syndrome) associated with abnormal electrical activity in the occipital areas has only rarely been reported. Our case is significant for the following reasons: 1) PLEDs maximal right and left occipital areas associated with bilateral visual loss has not previously been observed; 2) abnormal electrical activity in the occipital lobes may be a reversible cause of Anton's syndrome.