PubMed Health⌕ Search

Biomedical subjects

Ken Johkura

Publications and source records attributed to Ken Johkura.

11 recordsLinked to original sources
PubMed2006

Spike-wave stupor in a patient with metabolic disorder.

We report a 79-year-old woman with a decreased level of consciousness. Investigation revealed an elevated serum ammonia and a portal-systemic shunt on angiography. Thus, her symptoms were thought to be due to metabolic encephalopathy. Her electroencephalogram (EEG) showed bilaterally synchronous runs of three-phase waves consistent with the triphasic waves typically seen in metabolic encephalopathy. However, after intravenous administration of diazepam, the EEG abnormalities improved; indicating that her decreased consciousness was of epileptic etiology, consistent with spike-wave stupor. Therefore, even in the presence of a clearly defined metabolic disorder, triphasic waves on the EEG may not be due to metabolic encephalopathy; they may reflect an epileptic state precipitated by the metabolic disorder.

Aged↗
PubMed2005

Cortical involvement in Marchiafava-Bignami disease.

Marchiafava-Bignami disease (MBD), a rare complication of chronic alcoholism, is characterized by primary demyelination of the corpus callosum. We report two cases of MBD in which fluid-attenuated inversion recovery (FLAIR) and diffusion-weighted imaging studies revealed symmetrical hyperintense lesions in the cerebral cortex (particularly in the lateral-frontal regions) in addition to the callosal lesions, which suggests an association of diffuse cortical lesions such as Morel's laminar sclerosis with MBD.

Aged↗
PubMed2004

Vertical conjugate eye deviation in postresuscitation coma.

Vertical eye deviation in hypoxic coma is considered to be rare. In contrast, we found that in a consecutive series of 50 postresuscitation comatose patients, 28 (56.0%) developed tonic upward or downward eye deviation. We suggest that both the upward and the downward deviations resulted from diffuse cerebrocerebellar damage sparing the brainstem. Upward deviation is an early sign, whereas downward deviation appears later and generally implies a transition to the vegetative state.

Adult↗
PubMed2003

Clinical deterioration in Bickerstaff's brainstem encephalitis caused by overlapping Guillain-Barré syndrome.

A 37-year-old man developed an acute encephalitic condition after respiratory infection. His condition rapidly deteriorated, and he experienced ophthalmoplegia, tetraplegia, loss of brainstem reflexes and deep tendon reflexes, and deep coma. Electrophysiological evaluations indicated involvement of the peripheral nerve as well as the brainstem. Follow-up studies found acute progression of peripheral nerve damage. Serum anti-GQ1b IgG antibody was present. The initial condition was diagnosed as Bickerstaff's brainstem encephalitis, and subsequent overlapping of Guillain-Barré syndrome probably was responsible for the clinical deterioration. When unusual worsening is observed in clinically suspected encephalitis, neurologists must take into account the possibility of associated Guillain-Barré syndrome and related disorders.

Adult↗
PubMed2003

Combination of infarctions in the posterior inferior cerebellar artery and anterior spinal artery territories.

After an episode of vasodilator-induced systemic hypotension, a 75-year-old man developed ocular lateropulsion to the right, left-side-dominant quadriparesis, loss of superficial sensation below C4 dermatome level, and anuresis. Magnetic resonance imaging (MRI) showed infarcts in the right cerebellar hemisphere (posterior inferior cerebellar artery territory) and the upper cervical cord (anterior spinal artery territory); the combination of posterior inferior cerebellar artery (PICA) and anterior spinal artery (ASA) infarcts has not been reported previously. Angiography revealed severe stenosis in the bilateral vertebral arteries. Hemodynamic hypoperfusion of the stenotic vertebral arteries may cause this unusual combination.

Aged↗
PubMed2002

Pathophysiologic mechanism of convergence nystagmus.

The convergent eye movements in convergence nystagmus are reported to be opposed adducting saccades under excessive convergence drive. What occurs is a horizontal saccade of the adducting eye and a quick reversal of the abducting eye immediately after initiation of the original saccade. Accordingly, the opposed adducting saccades of the abducting eye have been explained by the dynamic overshoot mechanism. However, by electro-oculographic analysis of eye movements in a patient with convergence nystagmus, we found that the opposed adducting saccades of the abducting eye occurred not only after but also just before initiation of the original saccade. Our observation indicates that the opposed adducting saccades can occur without dynamic overshoot as the starter mechanism. Possibly, cessation of the discharge of omnipause neurons may lead to firing of the burst neurons for the medial rectus subnucleus via activation by the excessive convergence drive.

Aged↗