Surgical techniques for arteriovenous malformations in functional areas: focus on the superior temporal gyrus.

Direct surgical intervention of arteriorvenous malformations (AVMs) in functional areas has been accepted as a standard mode of treatment. However, safe and successful intervention requires that such factors as exact location, size, vascular supply, and drainage be considered. Importantly, surgical techniques must be individualized to each patient, based on hemodynamic anatomy of the AVM. This paper discusses AVMs in the superior temporal lobe, which have a complex neuronal anatomy and circulatory system; the authors present 22 patients with AVMs of various sizes and describe the surgical techniques specific for the indicated location. Surgical procedures adhered to the following principles: 1) avoid brain tissue removal; 2) preserve microcirculation; 3) maintain circulation of the isolated major draining vein to access the AVM core; 4) compartmental isolation; and 5) preservation of functional area cortex covering the AVM. All patients underwent total resection except one, who had a subtotal resection. Neurological and occupational recovery was remarkable except for partial hemianesthesia in one patient; two patients are still in rehabilitation. This is the first description of a direct surgical approach to AVMs in the superior temporal gyrus, where management is challenging because the lesions may extend elsewhere, such as to Broca's and Wernicke's areas. The results suggest that the procedure is promising.

Can somatosensory evoked potential monitoring predict energy dynamics during controlled hypotension?

Somatosensory evoked potentials and redox (reduction/oxidation ratio) of cytochrome a,a3 were studied simultaneously before, during, and after controlled hypotension used for arteriovenous malformation resection. These studies were also conducted before and after ED-IC (external-internal carotid) bypass procedures for treatment of patients with transient ischaemic attacks. The former served as an acute model and the latter as a chronic model of low blood flow (ischaemia). The use of non-invasive reflection spectrophotometry (for redox studies) in conjunction with somatosensory evoked potentials (SSEP) has demonstrated that metabolic and electrophysiological changes parallel each other during "controlled" hypotension. The authors conclude that an analysis of SSEP changes are valuable in the study of metabolic and functional states of the brain during controlled hypotension.

Safety limits of controlled hypotension in humans.

Controlled hypotension is a safe and convenient means of allowing a surgeon to perform intracranial aneurysm, arteriovenous malformation and vascular tumor surgery. The mean arterial pressure between 40 and 60 mmHg induces diminished pulsatile arterial pressure, thus preventing rupture of these abnormal vasculatures. It is still possible to maintain cerebral metabolism in the functional level within this 40-60 mmHg blood pressure range. This statement is based on our experience of the physical and neurological outcome of patients after surgery, and on analyses of somatosensory evoked potential and redox of cytochrome a, a3 in the mitochondria of the cerebral cortical cells.

Acute spontaneous cerebellar hemorrhage.

Acute spontaneous cerebellar hemorrhage presenting with ataxia, dysarthria, vomiting, dizziness, and coma is commonly the result of hypertension. Early diagnosis is possible, and appropriate treatment, if timely executed, may be lifesaving.

A case of arteriovenous malformation of the third ventricle: a clinical presentation and special features.

Rarely, a lesion simulating a colloid cyst of the third ventricle may present with obstructive hydrocephalus and headache. Experience with an arteriovenous malformation in this location is discussed.

Indication of Gasserian ganglion coagulation for trigeminal neuralgia.

(1) Adequately extensive production of 5-gram analgesia is essential for satisfactory control of pain. (2) 87% of the 95 cases which underwent Gasserian ganglion coagulation have obtained satisfactory control of tic pain. (3) Another 6% of the cases could have satisfactory control with repeated coagulation, judged by the extent of analgesia after the first coagulation. (4) Based on the above findings we can now generally predict efficacy of this procedure.

The fortune of a capacious spinal canal.

Injury to the spine may be either osseous, neural, or both. The neurological deficit may or may not be a reflection of the severity of the osseous injury. Patients having wide canals are more likely to have less neurological dysfunction than those having narrow canals.

Excision of multiple intracranial metastatic hypernephroma. Report of a case with a 7-year survival.

The authors report a case of cerebral and cerebellar metastatic renal carcinoma with 7-year survival without present evidence of recurrence following excision of both intracranial lesions and the primary lesion (by radical nephrectomy).

Myelopathy associated with cervical spondylosis: a frequently unrecognized disease.

Cervical spondylosis or chronic diskogenic disease of the cervical spine is a relatively common cause of myelopathy, but it is often not recognized or is incorrectly diagnosed. The clinical presentation may mimic several types of neurological disease including multiple sclerosis and amyotrophic lateral sclerosis. Even more frequently, and especially early in the course of the disease, neurologic impairment is not recognized and the symptoms are thought to be due to osteoarthritis. Early recognition of this condition is important since adequate treatment can prevent slowly progressive neurologic impairment. Knowledge of the pathophysiology of myelopathy due to cervical spondylosis and adequate radiographic evaluation will often lead to treatment that can prevent progressive spinal cord damage. Cervical spondylosis with myelopathy is one of the most frequently unrecognized and misdiagnosed, yet treatable, conditions affecting the nervous system.