Biomedical subjects

K Kohshi

Publications and source records attributed to K Kohshi.

40 records · Page 3Linked to original sources

PubMed1989

Overnight recordings of intracranial pressure and electroencephalography in neurosurgical patients. Part I: Intracranial pressure waves and their clinical correlations.

Simultaneous overnight recordings of intracranial pressure (ICP) and electroencephalography (EEG) were conducted on 85 neurosurgical patients with intracranial hypertension and/or ventriculomegaly. Intracranial pressure waves were classified into five types according to the pattern of appearance, and their correlation with sleep cycles and clinical conditions of patients were investigated. A-waves appeared exclusively in patients with long-standing intracranial hypertension, and episodic B-waves appeared in patients with chronic hydrocephalus or a postoperative tumor-free condition. When these episodic pressure waves appeared, the patients were conscious and sleep cycles including REM stage were observed. Persistent, high pressure B-waves were seen mostly in patients with an acute phase of intracranial hemorrhages. The consciousness of these patients ranged from drowsy to stupor. EEG showed alternate appearances of light sleep and waking rhythms in accordance with cyclic oscillations of B-waves which coincided with periodic, apneic respiratory rhythms. When markedly regular B-waves of moderately high pressure appeared continuously, the patients were severely impaired in consciousness and were mainly in a subacute phase of intracranial hemorrhages. EEG showed continuous slow activities and sleep stages were not scored in these patients. No characteristic clinical features were found in patients whose ICP remained within normal range without pressure waves throughout the recording.

Adolescent↗

PubMed1989

Overnight recordings of intracranial pressure and electroencephalography in neurosurgical patients. Part II: Changes in intracranial pressure during sleep.

Changes in intracranial pressure (ICP) during sleep were investigated in 37 patients with chronic intracranial hypertension or chronic hydrocephalus, in whom episodic pressure waves characterized by A-waves or episodic B-waves were seen in Part I of this paper. The patients were conscious, and sleep stages including REM sleep were observed in all of them. During non-REM sleep, ICP significantly rose in Stage II on many occasions, and was always lower in Stage IV than in other sleep stages. A marked elevation of ICP was seen in REM sleep. ICP changes during REM sleep were characterized by frequent appearances of the pressure waves; 88.9% of A-waves and 95.1% of episodic B-waves appeared during REM sleep. The initiation of REM sleep scored on EEG began 1 to 2 minutes prior to or at the onset of the episodic pressure waves. The episodic pressure waves are assumed to be induced by the intracranial conditions in REM sleep, when increased brain activity and reduced sympathetic tone are known to occur simultaneously.

Adolescent↗

PubMed1989

[Thrombosed AVM presenting temporal lobe epilepsy].

A rare case of thrombosed AVM presenting temporal lobe epilepsy is reported. A 27-year old man was admitted to our hospital because of a 7-year history of temporal lobe epilepsy. He had also suffered from generalized seizure since he was 6 years old. No neurological deficit was disclosed. CT scan demonstrated a small calcified mass lesion in the left temporal lobe which was not enhanced by contrast study. Skull X - P and cerebral angiography were normal. Low intensity area on T1-weighted MR image corresponded to the high density area on CT scan. T2-weighted MR image demonstrated that peripheral low intensity area was more prominent and extensive. Conventional EEG showed focal spike discharges from the left fronto-central lead, and subdural EEG recordings showed intermittent spike discharges from the medial side of the left temporal lobe. A 5 cm temporal lobectomy was performed and a thick fibrous mass adjacent to the hippocampoamygdala complex was removed. Histopathological examination demonstrated a thrombosed AVM surrounded by gliotic neural tissue.

Adult↗

PubMedDate not supplied

Neurological manifestations in Japanese Ama divers.

Repetitive breath-hold (BH) diving can lead to accumulation of nitrogen (N2) in blood and tissues, which may give rise to decompression illness (DCI). An unusual condition is "Taravana", the diving syndrome reported by Cross in the 1960s. That report generated wide discussion as to whether BH diving can cause DCI. Paulev was the first person to suggest the link between DCI and BH diving. He, a submarine medical officer developed symptoms of DCI after a series of BH dives, having proceeded the dives by spending time in a hyperbaric chamber at 20 meters for 8 minutes. Recently four professional Japanese BH divers (Ama) with histories of diving accidents were reported. Magnetic resonance imaging of these divers detected cerebral infarcts localized in the watershed areas of the brain. A survey conducted on their island revealed that many Ama divers had experienced stroke-like events. A clinical feature of DCI in BH diving is that the damage is limited to the brain. Although the mechanisms of brain damage in BH diving are unclear, N2 bubbles passing through the lungs or the heart so as to become arterialized are most likely to be the etiological factor.

Adult↗