Diagnosis and management of spontaneous cerebrospinal fluid-middle ear effusion and otorrhea.

OBJECTIVES/HYPOTHESIS: Spontaneous leak of cerebrospinal fluid (CSF) into the middle ear can occur in adults without a history of temporal bone trauma or fracture, meningitis, or any obvious cause. Therefore, clues may be lacking that would alert the otolaryngologist that fluid medial to an intact eardrum, or fluid emanating from an eardrum perforation, is likely to be CSF fluid. A review of relevant medical literature reveals that herniation of the arachnoid membrane through a tegmen defect may be congenital, or CSF leak may occur when dynamic factors (i.e., brain pulsations or increases in intracranial pressure) produce a rent in the arachnoid membrane. Because tegmen defects may be multiple rather than single, identifying only one defect may not be sufficient for achieving definitive repair. Data on nine cases of spontaneous CSF leak to the ear in adult patients from four medical centers are presented and analyzed to provide collective information about a disorder that can be difficult to diagnose and manage. STUDY DESIGN: Retrospective review of nine cases of spontaneous CSF middle ear effusion/otorrhea. RESULTS: The majority of patients presented with symptoms of aural fullness and middle ear effusion. Many developed suspicious clear otorrhea only after insertion of a tympanostomy tube. Two patients had multiple defects in the tegmen and dura, and five patients had meningoencephaloceles confirmed intraoperatively. Five patients underwent combined middle cranial fossa/transmastoid repair. Materials used in repair included temporalis fascia, free muscle graft, Oxycel cotton, calvarial bone, pericranium, bone wax, and fibrin glue. CONCLUSIONS: CSF middle ear effusion/otorrhea can develop in adults without a prior history of meningitis or head trauma or any apparent proximate cause. Although presenting symptoms can be subtle, early suspicion and confirmatory imaging aid in establishing the diagnosis. Because surgical repair by way of a mastoid approach alone can be inadequate if there are multiple tegmen defects, a middle fossa approach alone, or in combination with a transmastoid approach, should be considered in most cases.

Transsphenoidal meningoencephalocele in adults.

BACKGROUND: Transsphenoidal meningoencephalocele is a rare congenital anomaly, reported only in 14 adult patients. It may be subdivided into intrasphenoidal, extending into the sphenoid sinus, and true transsphenoidal, traversing the floor of the sinus and protruding into the nasal cavity or nasopharynx. METHODS: We present the eighth case of true transsphenoidal meningoencephalocele reported in an adult. We review the literature and highlight the differences in clinical presentation and therapeutic management between patients with intrasphenoidal and true transsphenoidal meningoencephalocele. CONCLUSION: Adult patients with intrasphenoidal meningoencephalocele often present with rhinorrhea and should be considered for transsphenoidal repair, whereas patients with true transsphenoidal meningoencephalocele should not undergo surgery, in view of the complex anatomy and the slow progression of symptoms.

Brain pH monitoring during ischemia.

BACKGROUND: Brain tissue acidosis can result from ischemia when cerebral blood flow reduction reaches a critical value. The portable, battery-operated Khuri pH monitor has been used previously in a large number of patients undergoing cardiopulmonary bypass surgery to monitor the intramyocardial pH during aortic clamping. It was found to be easy to use, reliable, and a strong predictor of myocardial preservation. The goal of this study was to evaluate the applicability of this monitor in the measurement of brain pH. METHODS: Fifteen New Zealand white rabbits underwent general endotracheal anesthesia. A right frontal craniotomy was performed and a pH/temperature glass electrode was inserted in the frontal lobe. Both common carotid arteries were exposed in the neck and prepared for occlusion. Three rabbits were used as control; their brain pH was recorded over 60 minutes. Twelve rabbits underwent bilateral common carotid artery occlusion of varying duration and their brain pH measurements were recorded. RESULTS: There was no significant difference in pH levels at baseline in the two groups (p = 0.604). There were significant differences in pH over time between the control and occlusion group (p = 0.016). The pH dropped steadily and significantly in the occlusion group (p = 0.008), whereas little change in pH was noted over time in the control group (p = 0.366). CONCLUSION: The portable Khuri pH monitor has been used by cardiothoracic surgeons to monitor the myocardium during bypass procedures. Our experimental pilot study found it to be reliable in measuring the brain pH and to be relatively simple to use. It is approved by the Food and Drug Administration (FDA). We believe it may be of benefit to neurosurgeons.

SPECT imaging in cerebral vasospasm following subarachnoid hemorrhage.

UNLABELLED: Cerebral vasospasm is a frequent complication after subarachnoid hemorrhage and contributes to overall morbidity and mortality. Arteriography is the standard test for determining the presence of vasospasm. A retrospective review of 16 patients with cerebral aneurysm was undertaken to assess the sensitivity and specificity of SPECT for diagnosis of vasospasm. Fourteen patients were hospitalized after subarachnoid hemorrhage and 2 patients were hospitalized for elective aneurysmal clipping. The patients' condition on discharge was correlated to clinical and SPECT evidence of vasospasm. METHODS: Vasospasm was defined as the new onset of neurological signs and symptoms not explained by rebleed or hydrocephalus. A total of 20 SPECT studies were performed for 16 patients during their admission and 14 of 16 patients had a single angiographic study. RESULTS: Thirteen of 16 patients had 14 episodes of clinical evidence of vasospasm and 14 SPECT studies were performed in these 13 patients. The sensitivity and specificity of SPECT in this retrospective study were 89% (8/9) and 71% (5/7), respectively. Our small sample of arteriograms yielded in comparison a sensitivity of 67% (2/3) and specificity of 100% (9/9). The one false-negative SPECT study occurred in conjunction with the one false-negative arteriogram in the presence of clinical findings consistent with vasospasm. Three false-positive SPECT studies occurred in 2 patients who had perfusion abnormalities in areas of normal CT findings without clinical or arteriographic evidence of vasospasm. Five of 5 patients who died became unresponsive as a result of clinically presumed vasospasm and 4 of 5 of these patients had diffuse or hemispheric SPECT perfusion defects. Of the 11 patients who survived, none became unresponsive; 1 of 11 had positive diffuse or hemispheric perfusion defects. CONCLUSION: SPECT is a sensitive and fairly specific test for corroboration of clinical findings of vasospasm. A negative SPECT study may obviate the need for arteriography. Unresponsiveness is the best predictor of poor outcome; however, hemispheric SPECT perfusion deficits are also associated with poor outcome.

Subintimal dissection of the vertebral artery in subluxation of the cervical spine.

The vertebral arteries appear to be particularly susceptible to injury in trauma of the cervical spine because of their close anatomical relationship to the spine; however, traumatic subintimal dissection of the vertebral artery is rare judging from the paucity of cases reported in the literature. The case of a patient who developed a visual field defect secondary to a fracture-subluxation of the cervical spine is reported. Angiography demonstrated an intimal dissection of the vertebral artery at the site of the fracture-subluxation resulting in thrombus formation and subsequently in emboli occluding the posterior temporal branch of the posterior cerebral artery. Early angiography is recommended if extracranial injury of the vertebral artery is suspected, and the institution of heparin therapy is necessary if a subintimal dissection is demonstrated.

Grading and outcome prediction of cases of aneurysmal subarachnoid haemorrhage by bedside xenon cerebral blood flowmetry.

Ninety-six patients with aneurysmal subarachnoid haemorrhage underwent serial measurement of regional cerebral blood flow throughout the period of their treatment over the period of 5 years (1983 to 1988). A portable bedside xenon cerebral blood flow machine was used in this study and the initial slope index (ISI) values showed a clear relationship between reduction of cerebral blood flow and deteriorating clinical grade. Furthermore, serial measurements showed a statistically significant relationship between drop of cerebral blood flow, at anytime during the course of the disease, and fatal or less than satisfactory outcome.

Synovial cyst of the cervical spine.

A case of acute posttraumatic myelopathy resulting from hemorrhage into synovial cysts bilaterally at the C-6, C-7 facet joints is presented. The pathogenesis of synovial cysts remains unclear, although reports in the literature have implicated trauma leading to cyst enlargement. Hemorrhage into the cavity of the synovial cysts resulted in epidural compression of the spinal cord in this patient. Because spinal synovial cysts cannot be unequivocally diagnosed preoperatively, other more common conditions must be considered in the differential diagnosis. Radiographic analysis including plain films, computed axial tomography, and metrizamide myelography are of value in establishing a neurological diagnosis. Surgical decompression and excision of the lesion may result in significant neurological improvement.

Temporary vascular occlusion during aneurysm surgery.

Premature rupture of a cerebral aneurysm during operation is a serious hazard. Direct pressure and suction may not always be effective in controlling the hemorrhage, and hasty dissection under such circumstances can cause serious injury to vital structures. In facing this risk, elective temporary arterial occlusion of parent vessels can be an advantage. Temporary clipping also may be helpful in the case of a giant aneurysm when the lesion must be opened and evacuated, or in the case of a thin-walled fundus tightly adherent to perforating vessels. Reduction of tension in the aneurysmal sac can be a valuable aid to safe dissection. The authors reviewed a total of 185 cases of intracranial aneurysm operated upon (L.S.) in the 5-year period between January 1980 and January 1985. Sixty-six patients (35.7%) underwent temporary arterial occlusion during the operations. Clinical outcome was excellent in 65.2% of the patients, good in 13.6%, fair in 12.1%, and poor in 3%. The mortality rate was 6.1%. No significant difference was found by comparing the 66 patients with temporary arterial occlusion with the 119 patients without occlusion. The longest occlusion time for the patients with excellent outcome was 23 minutes for bilateral A1 segments, 40 minutes for middle cerebral artery, 27 minutes 44 seconds for internal carotid artery, and 13 minutes 30 seconds for basilar artery. This study suggests that temporary arterial occlusion does not necessarily increase the overall mortality and morbidity in aneurysm surgery. When justified and used with caution it can be a valuable adjunct for the neurosurgeon.

Comparison of fast flow and initial slope index values for cerebral blood flow following subarachnoid haemorrhage.

Forty five patients with subarachnoid haemorrhage proved by lumbar puncture underwent serial measurements of cerebral blood flow and central conduction time. When the initial slope index (ISI) value for cerebral blood flow is considered there is a clear relationship between reduction of cerebral blood flow and deteriorating clinical grade. This relationship is not so clearly demonstrated using the fast flow (f1) value for cerebral blood flow. When cerebral blood flow is compared to central conduction time those patients with a central conduction time longer than 6 X 4 ms have a significantly lower CBFisi but not a significant lower CBFf1. Furthermore, using the ISI value, there is a linear relationship between the fall in cerebral blood flow and the lengthening of CCT below a threshold blood flow of about 35 ml/100 g/min. This relationship is not demonstrated with the CBFf1 value. It therefore appears that the ISI value for cerebral blood flow shows a greater correlation between clinical and electrophysiological events than the f1 value.

Decerebrate posturing with the syndrome of inappropriate secretion of antidiuretic hormone.

Decerebrate and/or decorticate posturing have not yet been described as possible features of the syndrome of inappropriate secretion of antidiuretic hormone. Cerebral edema and loss of brain electrolytes are contributing factors resulting in altered excitability of the neural membrane. We describe a patient who, on the eighth day after a head injury, presented with decerebrate posturing, which coincided with the development of the syndrome of inappropriate secretion of antidiuretic hormone, and which rapidly reversed with the correction of the hyponatremia. We believe that the syndrome of inappropriate secretion of antidiuretic hormone should be included in the differential diagnosis of abnormal posturing in the head-injured patient.

Anterior sacral meningocele. Current diagnosis.

One hundred fifty cases of anterior sacral meningocele have been reported in the world literature. This rare pathologic entity was first recognized and described by Bryant in 1837. We report a patient with an incidental anterior sacral meningocele. Our patient is the oldest reported in the literature. The incidental feature of this malformation is uncommon. We review the literature and discuss the clinical aspect, diagnosis, and treatment. Emphasis is placed on the current and optimal method of radiologic evaluation using computed tomography scan combined with metrizamide myelography.

A comparative study of the portable regional CBF monitor and the portable mean hemispheral CBF monitor: advantages and disadvantages in clinical practice.

CBF determination can provide additional valuable information which can be used in clinical practice to enhance our capabilities in patient evaluation. The initial techniques requiring intraarterial injections have been largely replaced by the noninvasive inhalation and intravenous methods. The recent refinement of microcomputers and the development of portable CBF monitors have made CBF determination a nontraumatic, dependable and easily repeatable examination at the patient's bedside. In this communication we compare a portable region CBF monitor and a portable mean hemispheral CBF monitor; we study their advantages and disadvantages in clinical practice. Emphasis is placed on the practical characteristics and the information provided by each monitor and its contribution to patient evaluation. Illustrative cases are presented.

Mean hemispheral cerebral blood flow changes after craniotomy. Significance and prognostic value.

The effects of craniotomy on cerebral haemodynamics remains controversial from a study of the literature. This report represents our experience with respect to CBF changes within 10 days of surgery. Our objective was twofold, first to study the effect of craniotomy on the cerebral circulation and second to determine whether the CBF pattern at different post-operative intervals could provide useful prognostic information. A total of 135 CBF measurements were performed at the bedside of 36 patients; 19 patients with an assortment of intracranial tumours and 17 patients with intracranial aneurysm in different clinical grades. Our results indicate a significant rise in CBF in the immediate post-operative period averaging 18% of the pre-operative value. We believe this reflects a normal reaction of the cerebral vasculature to the inevitable disturbance of surgery. Furthermore, this hyperaemia may be of prognostic value as it was observed in 85% of the patients with tumour discharged without post-operative deficit and in 80% of the patients with aneurysms discharged in clinical grade 1 or 2. This is in sharp contrast with its development in only 16% of the patients with tumour discharged with post-operative deficit and 16% of the patients with aneurysm discharged in grade 3 or 4. The study adds to the direct clinical utility of CBF determination as a prognostic tool.