Facial nerve involvement in pseudotumor cerebri.SK Bakshi, JL Oak, KP Chawla, SD Kulkarni, N Apte
Dept of Medicine, Seth GS Medical College, Parel, Bombay, Maharashtra.
A woman with history of bifrontal headache, vomiting and loss of vision was diagnosed as a case of pseudotumor cerebri based on clinical and MRI findings. Bilateral abducens and facial nerve palsies were detected. Pseudotumor cerebri in this patient was not associated with any other illness or related to drug therapy. Treatment was given to lower the raised intracranial pressure to which the patient responded.
Keywords: Abducens Nerve, Adult, Case Report, Cranial Nerve Diseases, etiology,Facial Paralysis, etiology,Female, Human, Magnetic Resonance Imaging, Paralysis, etiology,Pseudotumor Cerebri, complications,diagnosis,therapy,Steroids, therapeutic use,
Pseudotumor cerebri was recognised as a clinical entity by Quiricke in 1897. It is a syndrome of raised intracranial pressure in the absence of localizing neurological signs, intracranial mass lesions or cerebrospinal outflow obstruction. In the past twelve years, a number of studies have shown that pseudotumor cerebri can seriously and permanenty damaged the vision of adults and children. The incidence of pseudotumor cerebri is relatively high in women compared to men (9:1) in the age group 20-44 years1.
A twenty-three year old woman was admitted to our medical unit with complaints of bifrontal headache with vomiting persisting since eight days. Past history suggested unilateral headaches off and on since two years. Menstrual history revealed irregular cycles with oligomenorrhoea. There was no past history of fever, convulsions or a neurological deficit. There was no history of any drug intake.
On examination, the patient was conscious and alert. Vital parameters were normal. Blood pressure was 124/80 mm Hg. Examination of the eyes showed exposure keratitis with drying of the cornea. There was total loss of vision. There was no perception of light in both eyes. She had right lateral rectus palsy with bilateral lower motor neurone facial palsy. Fundus showed bilateral papilloedema. Her motor and sensory systems were normal and she had no meningeal signs. A clinical diagnosis of raised intracranial pressure was made. Her investigations showed Hb 15 gms%, WBC 8, 600/cu mm with polymorphs 73%, lymphocytes 26% and eosinophils 1%. ESR was 1 mm/lst hr. The serum electrolytes, blood sugar, blood urea and serum creatinine were normal. Serum calcium was 10.4 mg%. X-ray chest and skull were normal. CT scans were reported as normal and MR1 showed an incidental finding of "empty sell a syndrome" with no evidence of turgid, edematous brain. Lumbar puncture, done in the left lateral position, showed an opening pressure of 67 cm and a closing pressure of 32 cm of the CSF fluid. Examination of the CSF was within normal limits. The CSF protein was 28 mg%. No malignant cells were seen and the CSF VDRL was negative. EMG showed features suggestive of a degenerative facial neuropathy.
Based on the features described above, a diagnosis of pseudotumor cerebri with multiple cranial nerve palsies was made. The patient was referred to the neurosurgery department of our institution. She was advised to continue conservative management like mannitol, acetazolamide, dexamethasone and repeated lumbar puncture, failing which lumboperitoneal shunting was advocated. The patient responded to the treatment and the headache gradually subsided. Tarsorraphy was done for exposure keratitis.
At the time of discharge from the hospital, the exposure keratitis had completely recovered. Fundus examination revealed bilateral optic pallor.
Cranial nerve palsies have been described in pseudotumor cerebri by various authors. Abducens nerve palsy occurs in 10-60% of cases. Some authors have seen involvement of the medial, superior and inferior recti only2. McCammon et al3 reported a transient oculomotor nerve paralysis that resolved with large doses of steroids and repeated lumbar puncture, while Helper and Gorden4 have recorded a trochlear nerve palsy that resolved with large doses of steroids. A case of pseudotumor cerebri who developed complete bilateral opthalmoplegia with unilateral facial palsy has been reported5. In children, there are reports of unilateral facial nerve involvement, which resolved spontaneously6.
Kiwak and Levine7 have described a case of pseudotumor cerebri with facial diplegia, who showed complete resolution of signs and symptoms after adequate control of the increased intracranial pressure by lumboperitioneal shunting. The pathophysiology of cranial nerve palsies accompanying psudotumor cerebri is poorly understood, but in most cases probably represents a non-specific pressure relate phenomenon. Sixth nerve palsy probably occurs by stretching of the nerve across the petrous apex. Facial nerve involvement may be explained by increased intracranial pressure in the posterior fossa displacing the nerve so that it is stretched through its entire length in the facial canal.
As per modified Dandy criteria8, a diagnosis of idiopathic intracranial hypertension can be made based on the following points:
1. Signs and symptoms of raised intracranial pressure.
2. Absence of localizing findings on neurologic examination.
3. Absence of deformity, displacement or obstruction to the ventricular system and otherwise normal neurodiagnostic studies except for increased CSF pressure.
4. Awake and alert patient.
5. No other cause of raised intracranial pressure present. In our patient, all of the Dandy criteria were fulfilled.
Various associations with pseudotumor cerebri reported are obesity, steroid withdrawal, arterial hypertension, Addison’s disease, hypothyroidism, hyperthyroidism, hypoparathyroidism, iron deficiency anaemia9 and uraemia10.
Drugs causing Pseudotumor cerebri are tetracycline, nalidixic acid, nitrofurantoin, indomethacin, oral contraceptives, vitamin A and isotretinoin. Recently, benign intracranial hypertension has been found to be associated with lithium11 and danazol12 therapy in our patient, there was no history of drug intake.
We are thankful to the Dean, Seth GS Medical College and KEM Hospital for allowing us to publish this case report.