Weight and Abdominal Pressure-Induced Shunt Trouble in Patients With Shunted Normal Pressure Hydrocephalus: A Comprehensive Study on Pressure Environment of Shunt System.

Objectives: We identified a new type of shunt malfunction (SM) in patients with normal pressure hydrocephalus (NPH). It is induced by weight change and can be treated with valve readjustment. There were two types of SM as follows: Underdrainage induced by the weight gain and overdrainage induced by the weight loss. This study aims to elucidate this mechanism by assessing the shunt pressure environment. Methods: The total pressure environment of the shunt system was prospectively studied in patients with shunted NPH at Osaka Medical College Hospital from 1999 to 2005. We measured the pressure environment during the initial pressure setting of the valve by the intracranial pressure (ICP) guide, after setting the valve, and when SM was suspected. We evaluated ICP, intra-abdominal pressure (IAP), and hydrostatic and perfusion pressures of the shunt system in the sitting and supine positions. The target ICP for valve setting was empirically set at the range from -8 to -13 mm Hg in the sitting position, referring to the external auditory meatus. During the study period, we identified five cases of SM induced by weight change and assessed the changes in the pressure environment across pre-SM, SM, and post-SM. Results: In four cases of underdrainage, gait disturbance worsened with an average weight gain of 6.8 ± 1.2 kg. With weight gain, IAP and ICP increased by 8.8 ± 1.6 and 4.8 ± 1.0 mm Hg, respectively. Consequently, ICP increased to -6.5 ± 1.9 mm Hg. One overdrainage patient developed an asymptomatic chronic subdural hematoma (CSDH) with a weight loss of 10 kg. With the weight loss, both IAP and ICP decreased by 5 mm Hg, and concomitantly, ICP decreased to -18 mm Hg. In all patients, the valve readjustment restored their ICP to the target pressure. After the valve readjustment, the gait disturbance improved immediately, and the CSDH disappeared after 1 month. Conclusion: In patients with shunts, the weight change was linked to ICP via IAP. Due to the weight change, the underdrainage occurred when ICP was above the target pressure, and the overdrainage occurred when ICP was below it. We named this SM as the weight and abdominal pressure-induced shunt trouble. The patients with SM along with weight changes should be the first to be tried for the valve readjustment.

[Percutaneous vertebroplasty for vertebral compression fracture].

BACKGROUND: Percutaneous vertebroplasty has become an option for the treatment of painful osteoporotic compression fractures in patients in whom conservative medical management has failed. AIM: This paper assessed the effectiveness and safety of percutaneous vertebroplasty in patients with focal pain caused by compression vertebral body fractures. MATERIALS AND METHODS: Over a twenty-five-month period 63 patients underwent percutaneous vertebroplasty, and ten of these patients were subsequently retreated, for a total of 73 operations on 93 vertebrae. The patients were affected by osteoporotic compression fractures (n=57) or by benign or malignant infiltrative processes (n=6). All patients were examined at discharge and thereafter to assess the level of pain and investigate possible changes in the quality of life. The mean length of follow-up was 15.2 months. RESULTS: After treatment, almost 90% of patients reported complete disappearance or significant alleviation of the pain. In 7 of 63 of the patient (11%) there were small asymptomatic leakages of cement outside the vertebral body. A substantial number of patients with osteoporosis, 19% of the study population, experienced new fractures following treatment with vertebroplasty. DISCUSSION: Our experience confirms the effectiveness of vertebroplasty to pain caused by vertebral fractures. If the indications are strictly followed, improvement of symptoms is often immediate, allowing the return of mobility, and patient satisfaction with surgery is higher. The use of appropriate systems limits the number of complications.

Ruptured aneurysm at the cortical segment of the posterior inferior cerebellar artery.

We report a rare case of a ruptured aneurysm at the cortical segment of the posterior inferior cerebellar artery (PICA) with a branching complex that was feeding the bilateral cerebellar hemispheres. A 70-year-old woman suddenly sustained a severe headache and vomiting. CT scan revealed diffuse subarachnoid haemorrhage with fourth and lateral ventricular haemorrhage, which suggested typical aneurysmal bleeding in the posterior circulation. No aneurysm was detected on the initial angiogram. This angiogram also showed no significant evidence of other lesions that could be the origin of the bleeding. A third angiogram was performed 15 days from the ictus and revealed a distal PICA saccular aneurysm. The aneurysm was located at the cortical segment, and the artery was branching to both of the cerebellar hemispheres. This could be more clearly visualised during the ensuing operation, and neck clipping was performed. The patient recovered without neurological deterioration. Subarachnoid haemorrhage with blood in the fourth ventricle may indicate a ruptured aneurysm on the distal segment of the PICA with a branching variation, feeding the contra-lateral hemisphere, which is rarely located in this position.