Idiopathic normal pressure hydrocephalus: Theoretical concept of a spinal etiology

Combined Invasive Peripheral Nerve Stimulation in the Management of Chronic Post-Intracranial Disorder Headache: A Case Report

The introduction of ventricular shunts dramatically changed the outcome and quality of life of hydrocephalic patients. However, shunt surgery continues to be associated with numerous adverse events. Headache is one of the most common complications after shunt operation. It is often of prolonged duration, the symptoms resemble those of migraine, and pain does not respond to medication. We propose invasive peripheral nerve stimulation as a potential solution in the treatment of patients suffering from chronic headache associated with shunted hydrocephalus. A young woman presented with daily holocephalic headache with diffuse pain exacerbated by lying down. Imaging revealed panventricular enlargement and possible aqueduct stenosis. When a ventriculoperitoneal shunt was placed, clinical symptoms resolved. Nevertheless, she gradually exacerbated after a second valve replacement due to wound infection. Imaging revealed decompressed ventricles and appropriate shunt placement. The diagnosis of chronic post-intracranial disorder headache was set. Therefore, occipital nerve stimulation was applied and, considering that the patient did not have a total response, bilateral parietal stimulation was added. Three months after the combined PNS, she experienced total remission of headache. Combined PNS eases refractory headaches much more than occipital nerve stimulation alone and could be considered as a solution for shunted hydrocephalus-associated headache.

Association between subarachnoid hemorrhage-induced hydrocephalus and hydromyelia: pathophysiological changes developed in an experimental model

BACKGROUND

Subarachnoid hemorrhage-induced hydrocephalus (SAIH) can affect the prognosis of subarachnoid hemorrhage (SAH). The relationship between hydromyelia and SAIH has been rarely investigated. This experimental model aimed to identify the pathophysiological changes developed in the SAH and elucidate the relationship between hydromyelia and SAIH.

MATERIAL AND METHODS

25 female rabbits were randomly divided into three groups. The SAH group (n = 15), sham group (n = 5), and control group (n = 5). In the former group, the injection of 0.5 mL/kg of autologous blood was carried out into the cisterna magna on days 0 and 2. All animals were decapitated 21 days thereafter. Histological examinations of the medulla spinalis and brain samples were performed.

RESULTS

The mean volumes of the central channel were 1.054, 1.287, and 1.776 mm³ in the control, sham, and SAH groups, respectively (p = 0.028). The mean normal ependymal cell densities were 4.210, 3.602, and 2.923 cells/mm² in the control, sham, and SAH groups, respectively (p = 0.002). The mean ventricular Evans' indices were 0.31, 0.34, and 0.41, in the control, sham, and SAH groups, respectively (p = 0.006). Basement membrane rupture, desquamated ependymal cells, and central channel occlusion were observed on histological examinations of the SAH group.

CONCLUSIONS

Subependymal basement membrane destruction, blood cell accumulation on it, ependymal cell desquamation, increased cerebrospinal fluid (CSF) secretion, and increased ICP in the central channel that causes hydromyelia. When these pathological changes are chronically apparent, they may reflect on CSF pathways and cause permanent SAIH. Preventing long-time SAH-induced hydromyelia is believed to reduce the high rate of treatment-requiring SAIH.

Utility of surgical tumor resection for normal-pressure hydrocephalus associated with spinal schwannoma in the cauda equina: A case report and review of the literature

Introduction and importance

Generally, schwannoma increases the concentration of protein in cerebrospinal fluid (CSF) and causes normal-pressure hydrocephalus (NPH) due to absorption disorders of CSF. Cases of NPH caused by spinal schwannoma in the cauda equina are very rare. Here, we report a case of spinal schwannoma-related NPH in the cauda equina successfully treated by surgical resection alone.

Case presentation

A 78-year-old man presented with a 3-month history of gradually worsening memory disturbance. Neurological examination on admission showed dementia, hemiparesis of the left lower limb and gait disturbance. Computed tomography (CT) of the head revealed ventricular dilatation. CSF pressure was 150 mmH₂O. CSF analysis showed a normal cell count and a highly elevated protein level (3842 mg/dL). Magnetic resonance imaging (MRI) of the lumbar spine demonstrated an enhanced intradural extramedullary mass in the cauda equina at the L3-L4 level. We suspected schwannoma causing NPH and tumor resection with posterior L3–4 laminectomy was performed as a priority. Marked recovery of cognitive dysfunction and gait disturbance was evident postoperatively, and CT 4 months later showed narrowing of the ventricles.

Clinical discussion

If NPH due to spinal schwannoma is suspected as a result of lumbar puncture in a patient with dementia, confirmation of spinal schwannoma by lumbar MRI is absolutely necessary, and tumor resection alone may avoid unnecessary shunt placement.

Conclusion

These findings suggest that if a spinal schwannoma located in the cauda equina causes symptoms due to NPH, removal of the tumor should be considered a priority.

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We report a case of NPH with spinal schwannoma in the cauda equina treated by surgical resection alone.

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Cases of NPH caused by spinal schwannoma in the cauda equina are very rare.

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These findings suggest that if a spinal schwannoma located in the cauda equina causes symptoms due to NPH, removal of the tumor should be considered a priority.

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Elderly patients presenting with NPH should have cerebrospinal fluid analysis and MRI screening of the spinal cord.

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This report will be invaluable in elucidating the pathogenesis of NPH with spinal neurinoma and its natural history.

Correlation of hydromyelia with subarachnoid hemorrhage-related hydrocephalus: an experimental study

Although the central canal is an integral component of the cerebral ventricular system, central canal dilation has not been examined adequately during the progression of subarachnoid hemorrhage-related hydrocephalus (SAH-H). Central canal dilation-associated ependymal cell desquamation or subependymal membrane rupture has been rarely reported. Herein, we try to describe possible mechanisms of central canal dilation "Hydromyelia," developing after SAH. A total of 25 New Zealand hybrid female rabbits were recruited. Five served as controls, and five received sham operations. In the remaining animals (n = 15), 0.5 mL/kg of autologous blood was injected into the cisterna magna twice on 0 and 2nd days. Five of these animals died within a few days. A total of 10 survivor animals decapitated 3 weeks later, and the brains and cervical spinal cords were histologically examined. Central canal volumes, ependymal cell numbers on the canal surfaces, and the Evans' indices of the ventricles were compared. On histological examination, central canal occlusion with desquamated ependymal cells and basement membrane rupture were evident. The mean Evans' index of the brain ventricles was 0.31, the mean central canal volume was 1.054 mm³, and the normal ependymal cell density was 4.210/mm² in control animals; the respective values were 0.34, 1.287 mm³, and 3.602/mm² for sham-operated animals, and 0.41, 1.776 mm³, and 2.923/mm² in the study group. The differences were statistically significant (p < 0.05). Hydromyelia, an ignored complication of SAH-H, features ependymal cell desquamation, subependymal basement membrane destruction, blood cell accumulation on the subependymal cell basement membrane, and increased CSF pressure. Hydromyelia may be a significant complication following SAH.

Normal pressure hydrocephalus caused by a spinal neurinoma at the cauda equina level: a case report

Neurinomas are common space-occupying lesions located in the spinal canal. Many reports concerning their clinical characteristics, diagnoses, treatments, and operative results have been published. Some case reports have discussed spinal neurinomas located at the cauda equina level. However, there is little information on their natural history. Here, we report a case of spinal neurinoma located at the cauda equina level, which caused normal pressure hydrocephalus (NPH). All symptoms resulting from the NPH were resolved by tumor removal. These findings suggested that if a spinal neurinoma located at the cauda equina level causes symptoms due to NPH, then removal of the tumor should be considered, when appropriate removal procedures are possible.