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Show LETTERS TO THE EDITOR 279 this early age or it may appear much later ( Staraussberg et al., manuscript in preparation). Spastic paraplegia or paraparesis is uniformly present and is indeed the cardinal clinical sign in infancy. Cognitive functions are usually within the normal range. Brain computed tomography and magnetic resonance imaging, electroencephalography, and evoked potentials are usually normal except for low- amplitude visual evoked potentials with normal latency of P100. The gene frequency of 3- MGA in Iraqi Jews in Israel is 0.01 ( 3), whereas its incidence in other ethnic groups must be extremely low. Al Aqeel et al. ( 7) reported on 10 patients with 3- MGA from Saudi- Arabia. However, these patients had heterogeneous neurologic and clinical symptomatology distinctly different from the Iraqi- Jewish form. When optic atrophy is detected in infancy, childhood, or adolescence, especially in patients of Iraqi- Jewish stock, a search for 3- MGA should be mandatory. Unfortunately, the concentration of 3- MGA in amniotic fluid is not enough to enable prenatal diagnosis. This may be overcome when the search for a mutation in genomic DNA of the affected families will be successfully completed. The nature of the metabolic error causing 3- MGA is yet unknown. Defects in cholesterol synthesis, mitochondrial respiratory chain, leucine degradation, and peroxisomal functions have been suggested but not proven ( 8,9). Anat Kesler, M. D. Department of Neurology Sapir Medical Center, Meir Hospital Sackler School of Medicine, Tel Aviv University Kfar Saba, Israel Natan Gadoth, M. D. Department of Neurology Rabin Medical Center, Beilinson Campus Sackler School of Medicine, Tel Aviv University Petach Tikvah, Israel Rachel Straussberg, M. D. Department of Neurology Schneider Children's Medical Center Sackler School of Medicine, Tel Aviv University Petach Tikvah, Israel REFERENCES 1. Behr C. Die komplizierte, hereditar- familiare Optikusatrophie des Kindesalters. Klin Monatsbl Augenheilkd 1909; 47: 138- 60. 2. Miller NR. Walsh and Hoyt's Clinical Neuro- ophthalmology. Baltimore: Williams & Wilkins; 1982: 321- 25. 3. McKusick VA. Mendelian Inheritance in Man. Baltimore: Johns Hopkins University Press; 1992. 4. Costeff H, Gadoth N, Apter N, Prialnic M, Savir HA. Familial syndrome of infantile optic atrophy, movement disorder and spastic paraplegia. Neurology 1989; 39: 595- 7. 5. Costeff H, Elpeleg O, Apter N, Divery P, Gadoth N. 3- Methylglutanic aciduria in " optic atrophy plus." Ann Neurol 1993; 33: 103^ 1. 6. Elpeleg ON, Costeff H, Joseph A, Shental Y, Weitz R, Gibson KM. 3- methylglutaconic aciduria in Iraqi- Jews " optic atrophy plus." Dev Child Neurol 1994; 36: 167- 72. 7. Al Aqeel A, Rashed M, Ozand PT, et al. 3- Methylglutaconic aciduria: ten new cases with a possible new phenotype. Brain Dev 1994; 16: 23- 32. 8. Narisawa K, Gibson KM, Sweetman L, et al. Deficiency of 3- methylglutaconyl- coenzyme A hydratase in two siblings with 3- methylglutaconic aciduria. J Clin Invest 1986; 77: 148- 52. 9. Gibson KM, Lee CF, Wappner RS. 3- methylglutaconyl coenzyme A hydratase deficiency: a new case. J Inherited Metab Dis 1992; 15: 363- 6. Normal Pressure Pseudotumor Cerebri To the Editor: In their article '' ' Normal Pressure' Pseudotumor Cerebri," Green et al. ( 1) reported a case of an 18- year- old woman with clinical features suggestive of pseudotumor cerebri ( PTC) but without elevated intracranial pressure ( ICP). We would like to report a similar case. A 31- year- old, 5.4- feet tall, 130- pound white woman presented with an 18- month history of tinnitus, transient visual obscurations, and intermittent moderate headache. She was otherwise healthy with no other signs or symptoms of neurologic disease. She was not taking any medication. The clinical course had been characterized by left- sided tinnitus, brief transient visual obscurations in the left eye when bending, and moderate headache described as " fullness of the head" over 18 months. Ophthalmologic examination, repeated over 15 months, had shown bilateral disk edema that was not present on a previous funduscopic examination 3 years before. Computed tomographic scan and magnetic resonance imaging ( MRI) of the brain had been normal. A lumbar puncture had shown normal cerebrospinal fluid ( CSF), but the opening pressure had not been measured. After lumbar puncture, she experienced a severe postural headache related to CSF hypotension. Tinnitus and visual symptoms had resolved for about 3 months but had then recurred. Ophthalmologic examination by us showed normal visual acuity in both eyes. Pupils were normal. Slit- lamp examination and motility were unremarkable. Funduscopic examination showed bilateral chronic disk elevation worse on the left, with venous dilation. Goldmann visual fields showed bilateral enlarged blind spot and inferior nasal depression in the left eye. Neurologic examination was unremarkable. MRI of the brain and orbits with gadolinium was repeated and was again normal except for the presence of a partial empty sella turcica. A lumbar puncture showed an opening pressure of 180 mm H20 and normal CSF. Immediately after lumbar puncture, the patient reported resolution of ' ' fullness of the head," tinnitus, and transient visual obscurations. However, the day after, she complained of postural headache with nausea that spontaneously resolved within 20 days. J Neuro- Ophthalmol, Vol. 17. No. 4, 1997 280 LETTERS TO THE EDITOR Fluorescein angiogram showed bilateral disk leakage suggestive of disk edema, without autofluorescence. In addition, the presence of drusen was ruled out by normal orbital echography. Cerebral angiography ruled out cerebral venous thrombosis and dural fistula. She was discharged on acetazolamide ( 750 mg/ day). Three weeks later, bilateral tinnitus and transient visual loss recurred, whereas the post- lumbar puncture headache resolved. Lumbar puncture was then repeated and showed an opening pressure of 155 mm H20 and normal CSF. Again, although tinnitus and transient visual obscurations resolved within a few hours, the patient complained of severe postural headache that were treated with a blood patch after 2 days. Tinnitus recurred after the blood patch. After 2 years of follow- up, the patient is still treated with acetazolamide and is still complaining of tinnitus, intermittent transient visual obscurations, and moderate headache. Her visual acuity is still normal, and the fundus shows less severe, but persistent, bilateral disk edema. Repeated Goldmann and Humphrey 30- 2 visual fields are stable. We initially planned to perform an optic nerve sheath fenestration in the left eye, but this procedure was not performed because her visual function remained stable. The findings of a bilateral disk edema associated with transient visual obscurations, tinnitus, and headache with normal neurologic examination, neuroimaging, and CSF is suggestive of PTC. However, as in the case reported by Green et al. ( 1), our patient has a " normal intracranial pressure." We did not perform 48- h continuous subarachnoid ICP monitoring, but the opening pressure was ' ' normal'' on two separate measurements and our patient experienced low- pressure headache after the three lumbar punctures, suggesting that the CSF pressure was previously not elevated. As in the case reported by Green et al. ( 1), the presence of nonvisual symptoms that resolved with lumbar punctures ( i. e., tinnitus and fullness of the head) suggests that our patient represents a variation of PTC that has been called " normal pressure PTC" by Jonhnston et al. ( 2). Valerie Biousse, M. D. Marie Germaine Bousser, M. D. Department of Neurology Hopital Saint- Antoine Monique Schaison, M. D. Hopital Pitie- Salpetriere Paris, France REFERENCES 1. Green JP, Newman NJ, Stowe ZN, Nemeroff CB. " Normal pressure" pseudotumor cerebri. J Neuroophthalmol 1996; 16: 196- 8. 2. Johnston I, Hawke S, Halmagyi M, Teo C. The pseudotumor syndrome: disorders of cerebrospinal fluid circulation causing intracranial hypertension without ventriculomegaly. Arch Neurol 1991; 48: 740- 7. Normal Pressure Pseudotumor Cerebri To the Editor: Biousse and colleagues describe a woman with clinical symptoms and signs consistent with a diagnosis of pseudotumor cerebri ( PTC) without intracranial pressure elevation as defined by standard norms and as measured on two lumbar punctures. This case would constitute the third such reported patient with ' ' normal pressure PTC' ( 1,2). These three patients all had improvement of visual function and relief of other symptoms of classic PTC when intracranial pressure ( ICP)- lowering procedures were performed. As we were careful to note in our original case report ( 2), single measurements of ICP can miss pressure " peaks." Although continuous 48- h subarachnoid ICP monitoring may seem aggressive, it may still be appropriate in the evaluation of these very atypical presentations of PTC, especially if invasive intervention is contemplated. The monitoring may allow for complete fulfillment of the Dandy criteria and provide diagnostic as well as medicolegal support. If no elevated pressures are noted, the monitoring could be continued after surgical intervention, as in our case, to gauge the postoperative effect on ICP. We caution physicians to not make the diagnosis of " normal pressure PTC" too freely. It would be unfortunate if a patient with anomalous disks and headaches received an optic nerve sheath fenestration. We believe that if a patient presents with a clinical picture indicative of PTC, without evidence of ICP elevation on two separate lumbar punctures, more aggressive evaluation is needed. Serial visual fields, frequent fundoscopy with optic nerve photographs, and subjective evaluation of headaches as related to lumbar punctures should all be included in the diagnostic evaluation. Fluorescein angiography and optic nerve ultrasound should also be considered. Eventually, as more physicians become aware of this atypical presentation of PTC, new diagnostic criteria may be added to the Dandy criteria. We are grateful to Biousse et al. for sharing another case of this interesting and diagnostically challenging presentation of PTC. Jeffrey Paul Green, M. D. Nancy J. Newman, M. D. Emory University School of Medicine Atlanta, Georgia, U. S. A. REFERENCES 1. Johnston I, Hawke S, Halmagyi GM, Teo C. The pseudotumor syndrome: disorders of cerebrospinal fluid circulation causing intracranial hypertension without ventriculomegaly. Arch Neurol 1991; 48: 740- 7. 2. Green JP, Newman NJ, Stowe ZN, Nemeroff CB. " Normal pressure" pseudotumor cerebri. J Neuroophthalmol 1996; 16: 196- 8. J Neuro- Ophthalmol, Vol. 17, No. 4, 1997 |