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Biomedical subjects

J M Tew

Publications and source records attributed to J M Tew.

At least 127 records · Page 7Linked to original sources

Intratemporal schwannoma of the facial nerve.

Two patients with schwannomas that originated from the region of the geniculate ganglion of the facial nerve are reported. They presented with progressive facial nerve paralysis and variable disturbance of hearing. Computed tomograms demonstrated a mass lesion eroding the temporal bone (petrous portion) and extending into the middle fossa. The treatment consisted of complete excision of the tumor, and a hypoglossal-facial nerve anastomosis. Computed tomography should be performed on all patients with facial palsy of a progressive nature. Early diagnosis and surgical treatment of facial schwannoma should permit preservation of function of the facial and the acoustic nerves.

Adult↗

The sensory representation of the dura mater in the trigeminal ganglion of the cat.

The representation of the dura mater in the trigeminal ganglion was examined in the cat using the horseradish peroxidase (HRP) method. Following craniotomy a 50% solution of HRP was applied to various areas of the cranial dura and after a survival time of 48 h the trigeminal ganglion was processed. Cells in the first division gave rise to fibers innervating the medial aspect of the anterior fossa as well as the tentorium cerebelli. Labeled cells associated with the orbital roof were located predominantly in the dorsal and intermediate layers of the second division while the middle fossa was found to be represented mainly in the more dorsal strata of the third division. Labeled cells were smaller than the average ganglion cell.

Animals↗

Bilateral epidural hematomas.

Sixty-four cases of bilateral epidural hematomas were reviewed. The factors of patient age, direction of injuring forces, location of hematomas, presence of associated skull fracture, and time interval between injury and onset of signs and symptoms were analyzed. The results of this analysis show that bilateral epidural hematomas may develop slowly indicate that they occur with traumatic forces predominantly oriented in the anteroposterior direction, have fewer overlying fractures associated with them than unilateral epidural hematomas, and commonly contain venous blood. the differences between unilateral and bilateral epidural hematomas in direction of injuring forces, frequency of overlying skull fracture, and type of hemorrhage suggests that varying mechanisms may be responsible for production of these hematomas. Serial angiograms and CT scans have shown delayed accumulation of blood in bilateral epidural hematomas. This finding challenges the theory that epidural hematomas develop within minutes following injury.

Brain Injuries↗

Basilar impression and platybasia in osteogenesis imperfecta tarda.

Osteogenesis imperfecta, a rare, genetically transmitted disorder of bone, is known to be associated with the development of basilar impression and platybasia. These deformities of the base of the skull may cause neurosurgical abnormalities secondary to compression of the brainstem and hydrocephalus. The case is presented of a young boy with a family history of osteogenesis imperfecta tarda who suffered respiratory arrest during hospitalization. Cranial nerves and pyramidal tract signs were demonstrated. Roentgenograms showed severe basilar impression and hydrocephalus. Decompression of the brainstem and shunting were performed with improvement in the patient's neurological status. This case represents a rare by significant central nervous system complication of osteogenesis imperfecta. Early recognition and implementation of aggressive treatment are important if irreversible neurological deficits are to be avoided.

Adolescent↗

Pituitary enlargement and primary hypothyroidism: a report of two cases with sharply contrasting outcomes.

Primary hypothyroidism may be associated with pituitary enlargement. Two cases of pituitary enlargement with suprasellar extension associated with primary hypothyroidism are presented. In one patient, prompt regression of the pituitary enlargement occurred with replacement doses of L-thyroxine. In the second patient, there was progressive enlargement of the pituitary gland while the patient was on L-thyroxine therapy with documented normalization of serum levels of thyroid-stimulating hormone. We recommend repeat evaluation of all patients with pituitary enlargement that is thought to be secondary to primary hypothyroidism to document regression of pituitary size after L-thyroxine therapy.

Adult↗

a 10-year experience in the treatment of trigeminal neuralgia. Comparison of percutaneous stereotaxic rhizotomy and posterior fossa exploration.

Of 1000 patients with classic trigeminal neuralgia who were treated during the last 10 years, 90% had an initial favorable response to medical therapy, but 75% (750 patients) failed to achieve satisfactory long-term relief. Of these, 700 patients were treated by percutaneous stereotaxic rhizotomy (PSR) and 50 were selected for posterior fossa exploration (PFE). Of the 50 patients undergoing PFE, 82% had neurovascular contact at the trigeminal root entry zone, but only 46% were judged to have had significant neurovascular compression. Exploration was negative in 16% of patients and revealed neural compression by bone in 2%. Patients with neurovascular compression were treated by microvascular decompression (MVD); all other patients with exploratory surgery underwent partial sensory rhizotomy. At 3 years after PFE, 84% of patients are pain-free. Results are excellent in 68%, good in 12%, fair in 4%; 12% had a recurrence of their neuralgia. The 700 patients treated by P SR have been followed for 6 years. Results area excellent in 61%, good in 13%, fair in 5%, and poor in 1%; 20% had a recurrence. This study indicates that there is no significant difference in results between PSR and PFE in the treatment of trigeminal neuralgia. The concept that neurovascular compression is a mechanical factor in the etiology of trigeminal neuralgia was supported, but neurovascular compression was less common than previously reported. Percutaneous stereotaxic rhizotomy is a less formidable procedure than PFE, and is easily repeated. Recent technical advances have improved the results obtained with PSR. Therefore, PSR remains the procedure of choice for the majority of patients with trigeminal neuralgia.

Cranial Fossa, Posterior↗

Foreign body embolization of the middle cerebral artery: review of the literature and guidelines for management.

Two cases of traumatic middle cerebral artery occlusion secondary to migratory intravascular metallic pellets are presented. Surgical removal of the occlusive pellet was achieved in one patient, and vessel patency was restored. One patient recovered from his neurological deficit without surgical intervention. Factors such as the availability of a microvascular surgeon, the status of the neurological deficit resulting from the embolus, the time interval from injury to the proposed operation, and the extent of ancillary injuries sustained concurrently all bear weight on the decision to explore surgically or treat by medical measures. We believe that in cases of trauma an attempt to remove intravascular emboli is warranted to prevent migration of the embolus and distal propagation of thrombus, to avoid chronic sepsis, to prevent arterial erosion, and to restore the integrity of the vascular tree.

Adult↗

The prolonged Q-T syndrome presenting as a focal neurological lesion.

A patient with a prolonged electrocardiographic Q-T interval suddenly developed left hemiplegia after an episode of ventricular fibrillation. A CT scan showed a cerebral infarction in the right internal capsule. The prolonged Q-T interval, by virtue of its association with cardiac arrhythmias, may cause cerebral hypoperfusion that commonly results in generalized neurological deficits. The lack of evidence for embolization in this patient suggests that decreased cerebral perfusion was responsible for the genesis of her neurological signs and symptoms. The prolonged Q-T interval is an easily overlooked cardiac abnormality that must be considered in a patient who exhibits a focal neurological deficit.

Adult↗

Microsurgical treatment of intractable hemifacial spasm.

Ten patients with intractable hemifacial spasm were treated by posterior fossa exploration and microsurgical technique. These patients have been followed 1 to 5 years. The spasmodic motor disorder was related to compression of the 7th nerve or its exit zone at the brain stem by a dolichoectatic anterior inferior cerebellar artery in eight patients and to kinking and ectasia of the basilar or vertebral artery in two patients. In five patients, there were prominent arachnoidal adhesions in the cerebellopontine angle, and an arachnoid cyst was a component of the lesion in another patient. Additional conditions associated with hemifacial spasm included geniculate neuralgia, facial paresis, vertigo, hearing loss, and trigeminal neuralgia. The surgical morbidity and postoperative results are discussed.

Adult↗

Surgical management of the totally occluded internal carotid artery: a ten-year study.

Although surgical treatment of the stenotic and ulcerative internal carotid artery has been accepted as an effective approach to the management of cerebrovascular insufficiency, uncertainty and controversy have prevailed over the past two decades regarding the optimal management of the totally occluded artery. Over a 10-year period, 47 thromboendarterectomies were performed for recent total occlusion of the internal carotid artery. The patients were categorized and selected for surgery according to their neurologic manifestations and clinical status. Postoperative patency was studied by angiography and noninvasive laboratory tests, including oculoplethysmography, carotid phonoangiography, Doppler ultrasound, and ultrasonography. The patency rate achieved appeared to be related to the duration of carotid occlusion (100% within 7 days and 50% at 1 month). The overall patency rate was 68%. There were no operative deaths or morbidity. Dramatic improvement occurred in three patients who underwent surgery immediately after the onset of a major neurologic deficit. The results of this study indicate that surgical treatment for internal carotid occlusion should be considered in selected circumstances. Careful case selection and judicious timing of operation are mandatory.

Aged↗

Adrenoleukodystrophy: white matter disease with adrenal changes in 33-year-old man.

Patients with changes such as those that occur in relatively diffuse disorders of higher nervous function constitute a major diagnostic problem. We are presenting a patient with dysphasia, incoordination, difficulty concentrating, and weight loss with underlying organic changes. This 33-year-old patient had adrenoleukodystrophy (ALD), which is a sex-linked recessive disorder involving the adrenal glands with central nervous system demyelination. ALD usually manifests itself during childhood.

Adrenal Gland Diseases↗

Frontal sinus mucocele.

Although not uncommon, and certainly not rare, frontal sinus mucocele was seen in 4 cases by the authors. Since one of the cases was rather unusual, we were prompted to evaluate the subject and prepare this manuscript. Gradual onset of unilateral proptosis should make one suspicious of a mucocele involving the paranasal sinuses, the frontal and ethmoid being the 2 most common locations. Diplopia, due to limited ocular motility on upward gaze, along with proptosis and epiphora are frequently the presenting symptoms which, in one particular case, paradoxically improved at first with topical anti-inflammatory therapy . A team approach (ophthalmologist, radiologist, otorhinolaryngologist, and neurosurgeon) are essential for an accurate diagnosis and therapeutic approach to this problem. The use of a precut template from the Caldwell projection is a very useful device to outline the contours of the frontal sinus during surgery. The not-so-frequent use of abdominal fat to fill the frontal sinus cavity is presented with no apparent postoperative fat necrosis. A 5-year follow-up has shown the patient to be free of recurrences.

Diplopia↗