NOTES AND LETTERS
Central Pontine Myelinolysis Following Hyponatremia, Demonstrated by Computerized Tomography
Serum Electrolyte Levels for First Fitre Days of Treutment Serum Electrolvte Level (rnEa/L) Date
Sodium
Potassium
1/23/79 1/24/79 1/26/79 1/28/79
92 112 124 137
2.8 2.6 3.7 3.9
Carbon Chloride Dioxide 45 75
90 100
29 24 28 26
Robert B. Telfer, MD, and Edward M. Miller, M D The sequence of hyponatremia followed by quadriparesis, severe dysarthria, and dysphagia has been noted repeatedly in patients found to have central pontine myelinolysis ;CPM) at postmortem examination [2-41. The diagnosis of CPM was first described in 1959 [ 13 and has been difficult to confirm antemortem. Delayed brainstem evoked responses [5] have been reported to be useful. An abnormal pattern is nonspecific, however, in that several other disorders may give similar results. This report indicates that C T scanners with high spatial and contrast resolution make possible the antemortem demonstration of CPM.
(A)Axial C T brain .(can (noneribanred.A 2 x I .5 cm central zone of low density is demonstrated within the pons (arrows). (B) Section ro~tralt o A following injection of contrast material. The pontine lesion is seen separated into two symmetrical low-density zones that show slight peripheral enhancement (arrows).
A 51-year-old woman had had extreme weakness for a week prior to admission. For several weeks she had been treated for hypertension with propranolol, 80 mg twice a day, hydrochlorothiazide, 50 mg twice a day, potassium chloride, 15 ml twice a day, and an unknown sedative. Serum electrolyte values eight days before admission were: sodium, 119 mEq/liter; potassium, 3.4 mEq/liter; chloride, 80 mEq/liter; and carbon dioxide, 32 mEq/liter. Electrolyte determinations at admission included a sodium level of 92 mEq/liter (Table), serum osmolality of 197 mOsm, and urine osmolality of 348 mOsm. The antidiuretic hormone level was 8.1 pU/ml (normal, 0.4 to 5.3). Serum phosphate was 1.2 mgldl (improved rapidly). Thyroid function studies showed transient elevation. She was treated with 500 ml of 396 saline at a rate of 100 ml per hour. Fluid was restricted to 400 ml of 0.9% normal saline per day. H e r serum electrolytes returned to normal levels over the next five days (Table). During the first week the patient was lethargic but could talk and move her extremities. During the second week she seemed withdrawn and uncommunicative. She developed dysphagia and bilateral weakness of all extremities and for a few days had extensor plantar responses. H e r reflexes were brisk symmetrically without clonus. No sensory deficit was detected. She was incontinent of urine. During the third and fourth weeks she slowly improved. About five weeks after admission she was able to walk with assistance but had severe weakness in both upper extremities. At the time of From the Departments of Neurology and Radiology, University of California, San Francisco, School of Medicine and San Francisco General Hospital, San Francisco, CA. Accepted for publication June 10, 1979. Address reprint requests to Dr Telfer, 1800 Sullivan Ave, Suite 508, Daly City, CA 94015.
455
discharge, seven weeks after admission, she could swallow well, was continent, and could walk independently. She remained somewhat dysarthric. An initial C T scan with older equipment, performed 16 days after admission, showed no abnormality. A second C T scan, performed with a GE 8800 C T scanner 42 days after admission, revealed a well-circumscribed area of low density affecting the central portion of the pons anterior to the fourth ventricle (Figure, A). More rostrally, the lesion separated into two symmetrical lucent zones which showed a thin rim of enhancement following injection of contrast medium (Figure, B). These areas of radiolucency were thought to lie within the corticospinal and corticobulbar tracts of the brainstem. The clinical diagnosis was CPM. The findings o n C T scan placed the lesion at the site reported in postmortem studies [I]. Three months later our patient showed continued clinical improvement and no change on repeat C T scan.
References 1. Adams RD, Victor M, Mancall E L Central pontine myelinolysis. Arch Neurol Psychiatry 81:154-179, 1959 2. Burcar PJ, Norenberg MD, Yarnell PR. Hyponatremia and central pontine myelinolysis. Neurology (Minneap) 27:223226, 1977 3. Messert B, Orrison WW, Hawkins MJ, et al: Central pontine myelinolysis. Neurology (Minneap) 29:147-160, 1979 4. Schneck SA, Burks JS, Yarnell PR: Antemortem diagnosis of central pontine myelinolysis. Neurology (Minneap) 28:389, 1978 5. Stockard JJ, Rossiter VS, Wiederholt WC, et al: Brain stem auditory evoked responses in suspected central pontine myelinolysis. Arch Neurol 33:726-728, 1976
Reversal of an Afferent Pupillary Defect with Cold Water Drinking Jan S. C. Czarnecki, MD, FRCS(C) The afferent pupillary defect (or Marcus Gunn pupil) is a sign indicating that more information is reaching the midbrain from one eye than from the other and usually points to a lesion in one optic nerve [ 4 ] .Its onset can be as abrupt as the onset of the lesion causing the conduction loss in that optic nerve. Recovery is usually slow and matches the recovery rate of the injured fibers in that nerve. Once present, the afferent pupillary defect is usually a reliable and slowly changing sign. This is the report of a patient with a long history of multiple sclerosis in whom a right afferent pupillary defect was changed to a left afferent defect by the ingestion of cold water.
A 5 1-year-old woman with a twenty-year history of multiple sclerosis and recurrent episodes of transient neurological loss presented with a ten-day history of right retrobulbar pain on eye movement and visual loss in the right eye. She described a previous severe attack of optic neuritis in her left eye five years earlier, which had left her with reduced vision. The visual acuity was 20/600 in the right eye and 20/60 in the left. She had a right afferent pupillary defect. H e r left optic disc was atrophic, but the right appeared normal. After 20 minutes of constant ice-water drinking, vision improved to 20/50-2 in her right eye but remained 20/60 in the left. While she was cold and her vision had improved, a relative left afferent pupillary defect could be demonstrated. One week later the vision in the right eye had improved to 20/40 and she had no relative afferent pupillary defect. Eight weeks later the vision in the right eye had further improved to 20/25, though her left eye remained at 20/60. She had bilateral optic atrophy, more marked on the left, and a left afferent pupillary defect. No changes have occurred during the subsequent year. The signs and symptoms of multiple sclerosis may intensify with small increases in body temperature. The reverse has also been noted. Walsh and Hoyt [ 5 ] reported on a case of optic neuritis in which the vision improved transiently from 20/200 to 20170 with ice-water drinking. Regan et a1 [3] reported a decrease in the latency of the visual evoked response in patients with optic neuritis after the body temperature was reduced. The effects of temperature changes on demyelination have been studied by Rasminsky and Sears [ 2 ] and Rasminsky [I]. Increases of temperature as small as 0.5"C within the physiological range have been found to cause reversible conduction block at identifiable internodes of experimentally demyelinated rat ventral root fibers. The mechanism of the block is still unclear.
References 1. Rasminsky M: The effects of temperature on conduction in demyelinated single nerve fibers. Arch Neurol 28:287-292, 1973 2. Rasminsky M, Sears TA: Internodal conduction in undissected demyelinated nerve fibers. J Physiol (Lond) 227:323-350, 1972 3. Regan D, Murray TJ, Silver R: Effect of body temperature in visual evoked potential delay and visual perception in multiple sclerosis. J Neurol Neurosurg Psychiatry 40: 1083-1091, 1977 4. Thompson HS: Pupillary signs in the diagnosis of optic nerve diseases. Trans Ophthalmol SOCUK 96:377-381, 1976 5. Walsh FB, Hoyt FH: Clinical Neuro-Ophthalmology. Third edition. Baltimore, Williams & Wilkins, 1969, p 990
From the Department of Ophthalmology, Sunnybrook Hospital, University of Toronto Eye Clinic, 2075 Bayview Ave, Toronto, Ont, Canada M4N 3M5. Accepted for publication June 11, 1979
456 Annals of Neurology Vol 6 No 5 November 1979
Central Pontine Myelinolysis Following Hyponatremia, Demonstrated by Computerized Tomography
Serum Electrolyte Levels for First Fitre Days of Treutment Serum Electrolvte Level (rnEa/L) Date
Sodium
Potassium
1/23/79 1/24/79 1/26/79 1/28/79
92 112 124 137
2.8 2.6 3.7 3.9
Carbon Chloride Dioxide 45 75
90 100
29 24 28 26
Robert B. Telfer, MD, and Edward M. Miller, M D The sequence of hyponatremia followed by quadriparesis, severe dysarthria, and dysphagia has been noted repeatedly in patients found to have central pontine myelinolysis ;CPM) at postmortem examination [2-41. The diagnosis of CPM was first described in 1959 [ 13 and has been difficult to confirm antemortem. Delayed brainstem evoked responses [5] have been reported to be useful. An abnormal pattern is nonspecific, however, in that several other disorders may give similar results. This report indicates that C T scanners with high spatial and contrast resolution make possible the antemortem demonstration of CPM.
(A)Axial C T brain .(can (noneribanred.A 2 x I .5 cm central zone of low density is demonstrated within the pons (arrows). (B) Section ro~tralt o A following injection of contrast material. The pontine lesion is seen separated into two symmetrical low-density zones that show slight peripheral enhancement (arrows).
A 51-year-old woman had had extreme weakness for a week prior to admission. For several weeks she had been treated for hypertension with propranolol, 80 mg twice a day, hydrochlorothiazide, 50 mg twice a day, potassium chloride, 15 ml twice a day, and an unknown sedative. Serum electrolyte values eight days before admission were: sodium, 119 mEq/liter; potassium, 3.4 mEq/liter; chloride, 80 mEq/liter; and carbon dioxide, 32 mEq/liter. Electrolyte determinations at admission included a sodium level of 92 mEq/liter (Table), serum osmolality of 197 mOsm, and urine osmolality of 348 mOsm. The antidiuretic hormone level was 8.1 pU/ml (normal, 0.4 to 5.3). Serum phosphate was 1.2 mgldl (improved rapidly). Thyroid function studies showed transient elevation. She was treated with 500 ml of 396 saline at a rate of 100 ml per hour. Fluid was restricted to 400 ml of 0.9% normal saline per day. H e r serum electrolytes returned to normal levels over the next five days (Table). During the first week the patient was lethargic but could talk and move her extremities. During the second week she seemed withdrawn and uncommunicative. She developed dysphagia and bilateral weakness of all extremities and for a few days had extensor plantar responses. H e r reflexes were brisk symmetrically without clonus. No sensory deficit was detected. She was incontinent of urine. During the third and fourth weeks she slowly improved. About five weeks after admission she was able to walk with assistance but had severe weakness in both upper extremities. At the time of From the Departments of Neurology and Radiology, University of California, San Francisco, School of Medicine and San Francisco General Hospital, San Francisco, CA. Accepted for publication June 10, 1979. Address reprint requests to Dr Telfer, 1800 Sullivan Ave, Suite 508, Daly City, CA 94015.
455
discharge, seven weeks after admission, she could swallow well, was continent, and could walk independently. She remained somewhat dysarthric. An initial C T scan with older equipment, performed 16 days after admission, showed no abnormality. A second C T scan, performed with a GE 8800 C T scanner 42 days after admission, revealed a well-circumscribed area of low density affecting the central portion of the pons anterior to the fourth ventricle (Figure, A). More rostrally, the lesion separated into two symmetrical lucent zones which showed a thin rim of enhancement following injection of contrast medium (Figure, B). These areas of radiolucency were thought to lie within the corticospinal and corticobulbar tracts of the brainstem. The clinical diagnosis was CPM. The findings o n C T scan placed the lesion at the site reported in postmortem studies [I]. Three months later our patient showed continued clinical improvement and no change on repeat C T scan.
References 1. Adams RD, Victor M, Mancall E L Central pontine myelinolysis. Arch Neurol Psychiatry 81:154-179, 1959 2. Burcar PJ, Norenberg MD, Yarnell PR. Hyponatremia and central pontine myelinolysis. Neurology (Minneap) 27:223226, 1977 3. Messert B, Orrison WW, Hawkins MJ, et al: Central pontine myelinolysis. Neurology (Minneap) 29:147-160, 1979 4. Schneck SA, Burks JS, Yarnell PR: Antemortem diagnosis of central pontine myelinolysis. Neurology (Minneap) 28:389, 1978 5. Stockard JJ, Rossiter VS, Wiederholt WC, et al: Brain stem auditory evoked responses in suspected central pontine myelinolysis. Arch Neurol 33:726-728, 1976
Reversal of an Afferent Pupillary Defect with Cold Water Drinking Jan S. C. Czarnecki, MD, FRCS(C) The afferent pupillary defect (or Marcus Gunn pupil) is a sign indicating that more information is reaching the midbrain from one eye than from the other and usually points to a lesion in one optic nerve [ 4 ] .Its onset can be as abrupt as the onset of the lesion causing the conduction loss in that optic nerve. Recovery is usually slow and matches the recovery rate of the injured fibers in that nerve. Once present, the afferent pupillary defect is usually a reliable and slowly changing sign. This is the report of a patient with a long history of multiple sclerosis in whom a right afferent pupillary defect was changed to a left afferent defect by the ingestion of cold water.
A 5 1-year-old woman with a twenty-year history of multiple sclerosis and recurrent episodes of transient neurological loss presented with a ten-day history of right retrobulbar pain on eye movement and visual loss in the right eye. She described a previous severe attack of optic neuritis in her left eye five years earlier, which had left her with reduced vision. The visual acuity was 20/600 in the right eye and 20/60 in the left. She had a right afferent pupillary defect. H e r left optic disc was atrophic, but the right appeared normal. After 20 minutes of constant ice-water drinking, vision improved to 20/50-2 in her right eye but remained 20/60 in the left. While she was cold and her vision had improved, a relative left afferent pupillary defect could be demonstrated. One week later the vision in the right eye had improved to 20/40 and she had no relative afferent pupillary defect. Eight weeks later the vision in the right eye had further improved to 20/25, though her left eye remained at 20/60. She had bilateral optic atrophy, more marked on the left, and a left afferent pupillary defect. No changes have occurred during the subsequent year. The signs and symptoms of multiple sclerosis may intensify with small increases in body temperature. The reverse has also been noted. Walsh and Hoyt [ 5 ] reported on a case of optic neuritis in which the vision improved transiently from 20/200 to 20170 with ice-water drinking. Regan et a1 [3] reported a decrease in the latency of the visual evoked response in patients with optic neuritis after the body temperature was reduced. The effects of temperature changes on demyelination have been studied by Rasminsky and Sears [ 2 ] and Rasminsky [I]. Increases of temperature as small as 0.5"C within the physiological range have been found to cause reversible conduction block at identifiable internodes of experimentally demyelinated rat ventral root fibers. The mechanism of the block is still unclear.
References 1. Rasminsky M: The effects of temperature on conduction in demyelinated single nerve fibers. Arch Neurol 28:287-292, 1973 2. Rasminsky M, Sears TA: Internodal conduction in undissected demyelinated nerve fibers. J Physiol (Lond) 227:323-350, 1972 3. Regan D, Murray TJ, Silver R: Effect of body temperature in visual evoked potential delay and visual perception in multiple sclerosis. J Neurol Neurosurg Psychiatry 40: 1083-1091, 1977 4. Thompson HS: Pupillary signs in the diagnosis of optic nerve diseases. Trans Ophthalmol SOCUK 96:377-381, 1976 5. Walsh FB, Hoyt FH: Clinical Neuro-Ophthalmology. Third edition. Baltimore, Williams & Wilkins, 1969, p 990
From the Department of Ophthalmology, Sunnybrook Hospital, University of Toronto Eye Clinic, 2075 Bayview Ave, Toronto, Ont, Canada M4N 3M5. Accepted for publication June 11, 1979
456 Annals of Neurology Vol 6 No 5 November 1979
