The authors report a case of spontaneous spinal epidural hematoma causing paraplegia secondary to a qualitative platelet disorder from excessive garlic ingestion. The case also demonstrates satisfactory recovery from thoracic spinal epidural hematoma in a nonagenarian. Recovery from severe spinal cord compression can occur even in the very elderly.

An anti-siphoning valve for use in hydrocephalic shunt systems is described. The addition of this valve to the system effectively reduces the hazard of negative intraventricular pressure when the patient is sitting or standing. The formation of post-shunt subdural hematomas was prevented by temporary postoperative occlusion of the shunt using a percutaneously reversible occlusion valve, which is also described. KEY WORDShydrocephalie shunts hypotension subdural hematoma 9 reversible occlusion valve siphon effect ventricular anti-siphon valve 1.

A prospective multi-institutional study was carried out to evaluate automated percutaneous discectomy in the treatment of lumbar disc herniations. Of the 327 patients who prospectively met the study criteria and were followed for longer than 1 year, 75.2% were successfully treated. When patients (n = 168) who prospectively did not meet the study criteria were treated, the success rate was 49.4%. One case of discitis was reported; otherwise, no other serious complications were noted, and specifically no vascular or nerve damage was encountered. This study indicates that automated percutaneous discetomy can be used successfully to treat lumbar disc herniations with minimal morbidity and emphasizes the need for proper patient selection.

The authors report a case of spontaneous spinal epidural hematoma causing paraplegia secondary to a qualitative platelet disorder from excessive garlic ingestion. The case also demonstrates satisfactory recovery from thoracic spinal epidural hematoma in a nonagenarian. Recovery from severe spinal cord compression can occur even in the very elderly.

✓ The clinical course, roentgenological findings, and operative management of a patient with an ossifying fibroma (benign osteoblastoma) of the anterior cranial fossae are described. The tumor invaded the orbits, the ethmoids, the upper nasal cavity, and the right maxillary antrum. The differential roentgenological diagnosis is discussed.

✓ A case is presented in which puncture of the gallbladder and pneumothorax occurred during placement of a ventriculoperitoneal shunt. Treatment of these complications is outlined.

A study of differential pressure valves (DPV) used in the treatment of hydrocephalus was undertaken to determine their pressure-flow characteristics and compatability with the antisiphon valve (ASV). DPV could be classified into two groups: low resistance valves (LRV) and high resistance valves (HRV). The LRV maintains intraventricular pressure (IVP) near the closing pressure (CP) of the valve by permitting a high flow whenever CP is exceeded. The HRV regulates IVP by attempting to match inflow with some point on the pressure-flow curve of the valve. These characteristics were lost unless valve outlet pressure was maintained at atmospheric pressure. This could be accomplished by using a proximal DPV with an ASV at the DPV outlet, thus converting the DPV into a gauge pressure valve and preventing the ‘siphon effect’ seen with the use of a DPV alone.

Nine infants with myelomeningocele and hydrocephalus had cerebrospinal fluid formation and absorption studies before insertion of a ventriculoperi-toneal shunt. Six were also tested postoperatively. The preshunt formation rate varied from 0.21–0.42 ml · min^–1 and the cerebrospinal fluid absorption rate or CSF conductance (C_csf) varied from 0.008 to 0.031 ml · min^–1 · mm Hg^–1. The postoperative formation rate varied from 0.21 to 0.39 ml · min^–1. The postoperative CSF conductance (C_t) was calculated as the sum of C_csf and the shunt conductance (C_s). The relationship between the C_csf and C_s curves was determined by matching the sum of these curves to the postoperative data points using the method of least-squares. The data suggests that the shunt may work directly or indirectly to establish a new resting pressure; the latter by stabilizing the sagittal sinus pressure which preoperatively increased concomitantly with the CSF pressure and thus enhanced an already-existing absorption deficit.