Computed tomography demonstration of subarachnoid-pleural fistula.

A persistent left pleural effusion caused diagnostic difficulty in a young girl, 2 years after a road accident had rendered her paraplegic. Eventually, after instillation of a contrast medium into the pleural fluid, computed tomography showed a fistulous communication between the subarachnoid and pleural spaces at the level in the dorsal spine where trauma had occurred.

Paroxysmal facial pain in disseminated sclerosis treated by retrogasserian glycerol injection.

In the material of patients with trigeminal neuralgia treated by retrogasserian glycerol injection at the Karolinska Hospital, 23 cases (8%) were also diagnosed as suffering from disseminated sclerosis. These patients were often on carbamazepine treatment before the procedure, a regimen known to cause severe side effects and increase pre-existing symptoms in patients with multiple sclerosis. Following glycerol injection, more than 90% became pain-free within the first 2 months and 82% could discontinue drug therapy. This initial outcome corresponds well to the results in our larger series, but the long-term results in the group with multiple sclerosis is less satisfactory, with 61% recurrence at follow-up 8-79 months following treatment. In total 48% were pain-free at follow-up, following reinjections in 8 cases. In spite of less satisfactory long-term results, more than three-fourths of the patients wanted another glycerol injection after only low-dose trial with carbamazepine in case of recurrence.

Suppression of pain in trigeminal neuropathy by electric stimulation of the gasserian ganglion.

Lesions of the peripheral part of the trigeminal nerve may cause trigeminal neuropathy associated with severe pain. Such pain usually does not respond to carbamazepine and analgesics, and it is continuous and lacks the characteristic paroxysmal character of tic douloureux. These patients often present with complex changes of facial sensibility in the form of dysesthesia, hyperalgesia, and allodynia. The pain sometimes responds favorably to transcutaneous nerve stimulation, but direct stimulation of the trigeminal ganglion and rootlets via an implanted electrode provides a greater likelihood of pain relief. Fourteen patients diagnosed as having painful trigeminal neuropathy received implants of a gasserian ganglion-stimulating electrode. The mean follow-up period is 4 years (range, 1 to 7 years). Eleven of the patients have retained the pain-relieving effect, and 1 had pain disappear without further stimulation. Eight of the patients estimated their pain relief to be complete or very good. There were no serious complications, but in several of the patients the electrode had to be exchanged because the insulation of the lead wires broke. For the selection of patients for permanent electrode implantation, a method has been developed for trial stimulation via a percutaneous electrode introduced into the trigeminal cistern. Temporary trial stimulation can be performed for several days. It is concluded that stimulation of the trigeminal ganglion and rootlets with the aid of an implanted electrode may effectively relieve certain forms of trigeminal pain that are otherwise extremely difficult to manage.

Comparative analysis of experimental epidural and subarachnoid bleedings in dogs.

The difference in the course and the lethal mechanism between intracranial, subarachnoid and epidural bleedings was studied in a dog model under varying conditions. Subarachnoid bleedings were usually shortlasting, self-restricting, and generally survivable. The epidural bleedings differed quantitatively and qualitatively from the subarachnoid bleedings in being larger and having a longer duration. The difference seems related mainly to the development of an arterio-venous shunt in the epidural space during the bleeding. It is suggested that the epidural arterio-venous shunt may be of importance for the course and the lethal mechanism in epidural bleeding.

Trigeminal neuralgia treated by the injection of glycerol into the trigeminal cistern.

Seventy-five patients with trigeminal neuralgia were treated by the injection of 0.2 to 0.4 ml of glycerol by the anterior percutaneous route into the trigeminal cistern, which was visualized by the aid of contrast medium (metrizamide). Eighty-six per cent of the patients were completely free from pain after the treatment, which produced only minimal disturbance of facial sensitivity. No complications have been observed. It is suggested that glycerol acts mainly on partly demyelinated nerve fibers, which are assumed to be involved in the trigger mechanism.

Transoval trigeminal cisternography.

A new water-soluble contrast medium, metrizamide (Amipaque) was used to visualize the subarachnoid space within Meckel's cave. By a needle introduced through the foramen ovale, successful filling of the trigeminal cistern was accomplished in 48(80%) of 60 patients. Transoval trigeminal cisternography offers a possibility to control the position of the tip of the needle in various blocking procedures of the trigeminal ganglion, and may also be used for target localization in stereotactic radiosurgery in the treatment of trigeminal neuralgia.

The value of repeat pan-angiography in cases of unexplained subarachnoid hemorrhage.

Four-vessel angiography was repeated in 56 patients with confirmed subarachnoid hemorrhage in whom the initial investigation was negative. Only one aneurysm was demonstrated. The results suggested that, with good technique, careful observation, and a complete four-vessel cerebral angiography, a false negative rate of less than 2% can be achieved. It is suggested that to repeat pan-angiography is seldom justified unless further bleeding episodes occur.