Toru Fukuhara

The relationship between brain surface elastance and brain re-expansion after evacuation of chronic subdural hematoma

BACKGROUND Brain stiffness has been thought to be a factor affecting brain re-expansion after the evacuation of chronic subdural hematoma. METHODS As an index of brain stiffness, the pressure for compressing the brain using an ophthalmodynamometer was defined as brain-surface elastance. This elastance in 14 patients was measured and analyzed in relation to brain re-expansion. RESULTS Patients with an enlarged subdural space on computed tomography 1 month after the operation had higher elastance. There was a correlation between high elastance and high age. CONCLUSIONS Measuring the elastance after evacuation of the hematoma may help predict the persistence of a subdural space.

Induction of Cu,Zn-superoxide dismutase after cortical contusion injury during hypothermia

To determine the effect of hypothermia on superoxide injury after cerebral contusion, the induction of Cu,Zn-superoxide dismutase was examined 6 h after contusion in rats using Northern blotting. Cu,Zn-superoxide dismutase gene expression increased at the periphery of the contusion, which may indicate the severity of the superoxide stimulus. This increase was preserved after contusion under hypothermia, which may show that superoxide injury is still severe although brain edema is decreased.

Role of endoscopic third ventriculostomy at infected cerebrospinal fluid shunt removal.

OBJECT Cerebrospinal fluid shunt infection is distressing, especially in the pediatric population. Usually, infected CSF shunts are removed, and after temporary external CSF drainage, reinsertion of the CSF shunt is necessary. Unfortunately, it is not rare to encounter CSF reinfection after shunt renewal, and furthermore, the reinserted CSF shunt is at a considerable risk of malfunction. Endoscopic third ventriculostomy (ETV) is a potent option in managing CSF shunt infection, although ETV failure may occur more frequently when it is used to remove an infected shunt. The authors retrospectively evaluated CSF reinfection after using ETV during removal of infected CSF shunts; then the longevity of ETV and of successive reinserted ventriculoperitoneal shunts (VPSs) after ETV failure were also examined. METHODS Children with shunted hydrocephalus were retrospectively reviewed, and data on their initial CSF shunt infections were extracted. Thirty-six children underwent VPS reinsertion (the VPS group), and 9 underwent ETV after removal of the infected CSF shunt (the ETV group). As the primary outcome, ETV efficacy against CSF reinfection within 6 months was analyzed by comparing the reinfection rates, and the risk factors for CSF reinfection were analyzed by logistic regression. The longevity of the reinserted shunt in the VPS group was calculated using the Kaplan-Meier method, which was compared with ETV longevity as the secondary outcome, and also with the longevity of reinserted VPSs in the ETV group after ETV failure as the tertiary outcome. RESULTS Reinfection of CSF was seen in 27.8% of children in the VPS group. Among 9 children in the ETV group, only 1 (11.1%) had CSF reinfection. However, logistic regression analysis failed to show that performing ETV was a significant factor protecting against CSF reinfection: the significant risk factors were younger age at reinsertion of VPS or ETV (p = 0.037) and a history of shunt revisions (p = 0.011). The longevity of reinserted VPSs in the VPS group was calculated to be 658 ± 166.3 days (mean ± SE). Longevity of ETV was compared in the analysis of the secondary outcome, which was 929.2 ± 511.1 days, and there were no significant differences between these durations. Only 2 ETVs stayed patent, and a VPS was eventually implanted in the other 7 children. The longevity of this reinserted VPS in the ETV group, calculated based on these 7 children, was 2011.1 ± 540.7 days, which was confirmed to be longer than that in the VPS group (p = 0.031). CONCLUSIONS Although the protective effect of using ETV during removal of an infected CSF shunt on reinfection is marginal, the ETV longevity can be considered equivalent to that of reinserted VPSs. Even if ETV failure occurs, the reinserted VPS has significantly better longevity than a VPS reinserted without using ETV, and use of ETV during infected CSF shunt removal can be considered a potent alternative or at least an adjunct to VPS reinsertion.

A case of pontine lacunar infarction with ulcerative colitis

We present the case of a young man who experienced a sudden onset of pure motor hemiplegia in association with ulcerative colitis. Based on a review of earlier reports, ulcerative colitis was suspected to be the background disease leading to cerebral infarction. A cerebral infarction of the lacunar type in the right ventromedial aspect of the upper pons was seen on magnetic resonance images. These images detected small lesions in the brain stem, and were used to follow-up their transitions.

Selective posterior rhizotomy for painful spasticity in the lower limbs of hemiplegic patients after stroke: report of two cases.

OBJECTIVE AND IMPORTANCE:Selective posterior rhizotomy (SPR) has been performed mainly in children with cerebral palsy. Seldom has the use of SPR been reported for reduction of spasticity after stroke. We describe two elderly patients with hemiplegia who underwent unilateral SPR for pain caused by spasticity after stroke. CLINICAL PRESENTATION:The first patient was a 68-year-old woman who experienced spasticity and pain in her right leg during the chronic stage of a left cerebral infarction. The second patient was an 89-year-old man who had intolerable spastic pain in his left hemiplegic leg 3 months after a right cerebral infarction. INTERVENTION:Both patients underwent unilateral SPR on the spastic side to reduce the pain. After surgery, the patients’ pain resolved. In the first patient, the ability to perform activities of daily living also improved. CONCLUSION:Antispastic medications are often sufficient for treatment of post-stroke spasticity. In selected cases, however, SPR can be beneficial for improving painful spasticity.

Magnetic resonance imaging of patients with intention tremor

We evaluated the magnetic resonance images of the patients with intention tremor. Five patients out of seven had some atrophic structures or changes in signal intensity in the cerebello-rubral thalamic tract. Moreover, the T2-weighted images of the patients group detected the dentate and red nuclei more poorly than those of our control group. From these results, the etiological significance of the tract was confirmed and the mechanism of the intention tremor onset was discussed.

Superoxide scavenging activity in the extracellular space of the brain in forming edema.

We carried out a time course study of cerebral superoxide scavenging activity using a modified microdialysis technique. Twelve cats were divided into two groups; six were the reperfusion injury models, and six were cold injury models. In the reperfusion injury model, dialysates were collected during 60 minutes of middle cerebral artery occlusion and at 300 minutes during reperfusion. In the cold injury model, dialysates were collected 240 minutes after the injury. Regional cerebral blood flow on the injured side decreased during occlusion in the reperfusion injury model and 60 minutes after injury in the cold injury model. In the reperfusion model, superoxide scavenging activity, as determined with electron spin resonance, increased in the first 30 minutes and decreased 300 and 330 minutes after occlusion. In the dialysate, albumin increased 180 minutes after cold injury, which may show the progress of vasogenic edema. An increase in water content was observed on the injured side of both models, and a correlation between water content and superoxide scavenging activity was found in the reperfusion injury model. By this technique, a method of detecting the alteration of superoxide scavenging activity in the extracellular space of the brain was established.

Delayed germinal matrix hemorrhage induced by ventriculoperitoneal shunt insertion for congenital hydrocephalus

Germinal matrix hemorrhages (GMHs) are typically seen in preterm neonates during the first 4 days of life. The authors encountered 2 children with late-onset GMH subsequent to ventriculoperitoneal (VP) shunt insertion for congenital hydrocephalus. Both children were delivered at full term with normal body weight, although they were compromised with the preceding hypoxic events prior to shunt insertion. The first case involved a female infant with severe craniofacial deformities. Because of aspiration pneumonia related to the comorbid upper airway stenosis, endotracheal intubation with intermittent mechanical ventilation was necessary. The associated congenital hydrocephalus was treated with VP shunt insertion when she was 35 days of age, and GMH was confirmed 1 week after shunt placement. During a period of conservative observation, the hemorrhage resolved without any neurological deterioration. The second case involved a male infant with a large intraparenchymal cyst on the left parietal portion. He was intubated for pneumonia at 1 month of age. He had associated congenital hydrocephalus that was progressive, and he was treated with VP shunting at 69 days of age, after his pneumonia had resolved. Postoperative GMH was confirmed, although hydrocephalus was well controlled by VP shunt insertion. Observed conservatively, he fared well and the GMH resolved. These 2 cases had unique features in common; both had congenital anomalies in the CNS and respiratory problems before shunting. The hypoxic insults on the residual germinal matrix layer and sudden decrease in CSF pressure may relate to the occurrence of these late-onset GMHs.

Histological evidence of intraoperative monitoring efficacy in selective dorsal rhizotomy

PurposeIt has been advocated that intraoperative electrophysiological monitoring is mandatory in selective dorsal rhizotomy (SDR). However, it is still uncertain whether the monitoring procedure effectively differentiates dysfunctional rootlets. We histologically analyzed sectioned rootlets in SDR, in order to confirm the efficacy of the monitoring.MethodsSeven children with cerebral palsy underwent SDR on the same protocol. The pieces of their sectioned nerve rootlets from L5 were examined histologically using an electron microscope. In each patient, two nerve rootlets, one with the most abnormal response to intraoperative electrical stimulation and the other with the least abnormal response, were examined. The electron microscope findings of the rootlets were compared with the electromyography (EMG) findings in the intraoperative stimulation.ResultsAmong 14 examined nerve rootlets, definite abnormal EMG findings were seen in 5, which were 4 clonuses and one bilateral spread. All five rootlets with abnormal EMG findings showed axonal degenerations except one case, whose finding was dysmyelination. On the contrary, in the nine rootlets with normal EMG findings, eight rootlets had histologically minimum changes limited to the myelin sheath and one rootlet had dysmyelination without axonal degeneration.ConclusionsThe nerve rootlets with abnormal EMG findings in the intraoperative stimulation have definite histological abnormalities. This indicates that intraoperative monitoring is a meaningful method for identifying the nerve rootlets to be sectioned. This finding should be reminded as a precaution when considering nonselective dorsal rhizotomy, especially, for children who are expected to stand up after the surgery.

Peripheral sensory neuropathy observed in children with cerebral palsy: is chronic afferent excitation from muscle spindles a possible cause?

IntroductionPeripheral sensory neuropathy is known to be associated with several medical conditions; however, it has not been reported in patients with cerebral palsy. Authors have observed pathological changes in the sensory nerve rootlets taken during selective dorsal rhizotomy. This paper reports a possible novel cause of peripheral sensory neuropathy: the chronic afferent excitations from muscle spindles.Case reportSensory nerve rootlets on L5 were taken for histological evaluation from two children with cerebral palsy during selective dorsal rhizotomy, performed for their leg spasticities. Rootlets with clonus reaction against intraoperative electrical stimulation show dysmyelination, and in one child, axonal degeneration can also be observed. Rootlets with normal reaction have only minimum changes on their myelin sheath.ConclusionAs cerebral palsy is a typical upper motor neuron disorder, peripheral sensory neuropathy is unexplained. Since observed neuropathy is mainly on the myelin sheath, the etiology is considered to be the chronic overload of afferent impulses from muscle spindles in the spastic muscle.