Clinical and electrodiagnostic findings in copper deficiency myeloneuropathy.

INTRODUCTION: Copper deficiency is an increasingly recognised cause of neurological impairment. This retrospective review highlights clinical and electrodiagnostic findings in patients diagnosed at our institution with copper deficiency. METHODS: Clinical, radiographic and electrodiagnostic findings were reviewed in patients with evidence of copper deficiency. Patients with other potential causes of myelopathy or neuropathy were excluded. RESULTS: The predominant clinical feature in all six patients was a sensory ataxia, resulting in marked gait unsteadiness. Nerve conduction studies and needle EMG were performed in all patients and revealed a mild to moderate distal, axonal, sensorimotor peripheral neuropathy. Median and tibial somatosensory evoked potentials were abnormal in all five patients in which it was performed, showing impaired conduction in central or proximal peripheral somatosensory pathways. CONCLUSIONS: This pattern of electrodiagnostic findings suggests that impairment in somatosensory pathways demonstrated by somatosensory evoked potential testing is the main cause of the sensory ataxia in patients with copper deficiency.

De novo mutation in the Notch3 gene causing CADASIL.

CADASIL, an autosomal dominant arteriopathy responsible for stroke and dementia, is caused by strongly stereotyped mutations in the Notch3 gene. We report a patient with a condition strongly suggestive of CADASIL (migraine, stroke, and white matter abnormalities), except that this patient did not have any first-degree relatives with similar symptoms. This patient carried a heterozygous Arg182Cys mutation in the Notch3 gene; this mutation was absent in his two biological parents. These data demonstrate the occurrence of a de novo noninherited mutation in the Notch3 gene, which indicates that CADASIL should not be rejected in the absence of a family history. Therefore, our finding suggests that CADASIL may be more frequent than anticipated.