Unusual exocrine complication of pancreatitis in mitochondrial disease.

No association between mitochondrial disease and pancreatitis has yet been established, although diabetes mellitus and diseases caused by exocrine insufficiency, such as Pearson syndrome, are the commonest pancreatic complications of mitochondrial diseases. Here, we report 2 cases of mitochondrial disease complicated by pancreatitis as an unusual pancreatic exocrine manifestation. One patient was a 10-year-old girl with mild retardation of psychomotor development who had experienced recurrent pancreatitis since the age of 4years. Chronic progressive external ophthalmoplegia (CPEO) due to m.8344A>G mutation was diagnosed when the patient was 10years old. The other patient was a 28-year-old woman who was diagnosed with mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS) due to m.3243A>G mutation at 10years of age. She had experienced regular recurrent vomiting since the age of 16 and suffered an episode of critical pancreatitis at 23years. In both cases, no possible etiological, morphological, or genetic factors for pancreatitis were identified, including anomalous pancreaticobiliary duct. A combination therapy of the standard treatment for chronic pancreatitis and supportive therapy for mitochondrial energy production may be beneficial to prevent the recurrence of acute pancreatitis complicating mitochondrial diseases. The pathophysiological mechanism of pancreatitis in mitochondrial disease has not been adequately established; however, our observations suggest that pancreatitis should be included in the list of pancreatic complications of mitochondrial disease.

A magnetoencephalographic study of negative myoclonus in a patient with atypical benign partial epilepsy.

PURPOSE: To clarify the neurophysiological mechanism of epileptic negative myoclonus (NM) of a patient with atypical benign partial epilepsy whose NM was completely suppressed with ethosuximide. METHODS: Polygraphic recordings of whole-head type magnetoencephalography (MEG), EEG and electromyography were made during NM of the bilateral hands. The silent period of 200-400 ms duration in the bilateral biceps muscles was associated with paroxysmal spikes on EEG and MEG. Single equivalent current dipoles (ECD) were calculated for each spike component associated with NM and the estimated generator sources of spikes were superimposed on the patient's head MRI. RESULTS: The magnetic fields of each peak associated with NM showed clear single dipole pattern and ECDs of each peak were located in the neck and orofacial division of the primary motor cortex. CONCLUSIONS: Abnormal firing of the neck and orofacial division of the primary motor cortex was associated with NM generation. Taking the beneficial effect of ethosuximide (a T-type Ca2+ channel blocker in thalamic neurons and the corresponding cortex) and the MEG result together, it is suggested that abnormal interaction of the thalamo-cortical network might be closely related to the pathogenesis of NM.