Awakenings from persistent vegetative state: report of three cases with parkinsonism and brain stem lesions on MRI.

Three patients with a persistent vegetative state after severe head injury are reported. They recovered from a prolonged disturbance of consciousness after the administration of levodopa. These patients all had parkinsonian features. On magnetic resonance imaging, the distribution of lesions implied a diffuse axonal injury involving the substantia nigra or ventral tegmental area. The existence of patients whose dopaminergic systems may have been selectively damaged by a severe head injury should be recognised because such individuals may respond to levodopa treatment.

[A case of cardiogenic cerebral embolism with successful recanalization: apparent diffusion coefficient analysis for prediction of reversible cerebral ischemia].

A 54-year-old woman complaining of left hemiplegia was transferred to our hospital. Computed tomography on admission demonstrated normal. Electrocardiogram showed atrial fibrillation. Cerebral blood flow (CBF) was decreased in both the cortex and the perforator territory of the right middle cerebral artery (MCA), whereas the apparent diffusion coefficient (ADC) in the cortex was normal. Digital subtraction angiography (DSA) revealed an occlusion of the right MCA (M 1 proximal) with collateral flow from the right anterior cerebral artery (ACA) to the territory of the right MCA. After intra-arterial injection of tissue-plasminogen activator (t-PA), DSA showed partial recanalization, and the symptoms of the patient improved considerably. Five days after that, the patient deteriorated again and showed disturbance of consciousness and left hemiplegia. In this episode, both CBF and ADC in the cortex of the right MCA were decreased. DSA revealed an occlusion of the right internal carotid artery (ICA) and collateral flow from the right ACA to the territory of the right MCA disappeared. After intra-arterial injection of t-PA, DSA showed partial recanalization with collateral flow from the right ACA, and the symptoms of the patient improved. DSA 5 weeks after onset showed complete recanalization of both the right MCA and the ICA. The patient was diagnosed as both mitral and aortic stenosis and regurgitation (MSR + ASR) and underwent an operation for both mitral and aortic value replacement. She was discharged with no neurological deficit 4 months after onset. ADC analysis is especially useful for the prediction of reversible ischemic damage and the prevention of hemorrhagic transformation and fatal edema in acute ischemic stroke.

[Clinical usefulness of diffusion-weighted magnetic resonance imaging in patients with ischemic cerebrovascular disease].

Diffusion-weighted magnetic resonance imaging was performed to determine the detectability of ischemic changes in patients with ischemic cerebrovascular disease. We retrospectively reviewed 103 patients with symptoms suggestive of ischemic cerebrovascular disease. All patients underwent computed tomography, routine magnetic resonance imaging, and diffusion-weighted imaging. Of 103 patients, 18 were imaged within 3 hours after onset, 57 were imaged between 3 and 24 hours, and 29 were imaged between 24 and 144 hours. Eighty-eight patients were diagnosed as ischemic cerebrovascular disease. Magnetic resonance imaging was performed at a 1.0 Tesla clinical machine using single-shot spin-echo/echo-planar imaging sequence. In each case, three sets of DWI with motion-probing gradient pulses in the x, y, and z directions were taken. The detectability of ischemic changes of each imaging modality was compared. DWI detected ischemic changes in 83 of 88 cases with clinical diagnoses of cerebral ischemia(sensitivity; 94.3%). In contrast, DWI showed negative findings in 15 of the 15 patients with diagnoses other than cerebral ischemia(selectivity; 100.0%). DWI detected ischemic changes in 16 out of 18 patients(88.6%) within 3 hours after the onset. In contrast, T 2-weighted image did not detect any ischemic changes in the same period. These results suggest that DWI is considered to be highly useful for the early diagnosis of cerebral ischemia.

[Ketamine infusion therapy for refractory neuralgia in spinal disease: report of two cases].

We report two cases of refractory pain in a spinal disease. One case was a 60-year-old male who presented intractable pain in bilateral upper extremities after anterior fusion (C5/6, 6/7) for cervical spondylosis. The other was a 63-year-old female who also had intractable pain in the left anterio-lateral chest wall with no remarkable past history. Both cases were refractory to nonsteroidal anti-inflammatory drugs (NSAIDs) or minor tranquilizer or local anesthesia with bupivacaine. However, their pain was significantly relieved by the intravenous administration of a test dose (5mg) of ketamine which is a noncompetitive blocker of N-methyl-D-aspartate (NMDA) receptors. As for case 1, the effect of the injection of the test dose lasted, so continuing infusion therapy of ketamine was cancelled. In case 2, recurrence of the pain was recognized gradually. She underwent continuing infusion therapy of 2mg/kg of ketamine, and it brought about continued pain relief. We conclude that ketamine infusion therapy should also be considered for therapy of refractory neuralgia in spinal disease.

[A case of primary brain-stem injury recovered from persistent vegetative state after L-dopa administration].

A 51-year-old male was transferred to our hospital just after traffic accident. On admission, the patient was comatose (Glasgow Coma Scale of 6) and showed a left hemiparesis with a left oculomotor nerve palsy. Computed tomography demonstrated a traumatic subarachnoid hemorrhage without mass lesion. Magnetic resonance imaging showed high intensity lesions on the left dorsolateral midbrain and the right cerebral peduncle. The distribution of lesions implied diffuse axonal injury involving dopaminergic systems such as the substantia nigra and the ventral tegmental area. After several months of conservative management, the patient showed no recovery and was diagnosed as persistent vegetable state. The administration of L-dopa was then started and the patient showed remarkable neurological improvement. Therefore the patient's neurological status was thought to be modified with primary brain stem injury and accompanying traumatic Parkinson's syndrome. It is important to understand "pseudo" persistent vegetative state in the management of patients showing prolonged consciousness disturbance. L-dopa should be considered as the drugs of pharmacological intervention for the patients of masked parkinsonism behind "pseudo" persistent vegetative state whose dopaminergic systems might have been damaged.