|Year : 2019 | Volume
| Issue : 1 | Page : 34-38
Hyponatremia correction causing extrapontine myelinolysis
Binoy Damodar Thavara1, Harsha Padikkal Veettil2
1 Department of Neurosurgery, Government Medical College, Thrissur, Kerala, India
2 Department of Pulmonary Medicine, Government Medical College, Thrissur, Kerala, India
|Date of Submission||29-Apr-2019|
|Date of Acceptance||21-May-2019|
|Date of Web Publication||20-Jun-2019|
Dr. Harsha Padikkal Veettil
Department of Pulmonary Medicine, Government Medical College, Thrissur - 680 596, Kerala
Source of Support: None, Conflict of Interest: None
Rapid correction of hyponatremia will result in extrapontine myelinolysis (EPM). We report a case of 25-year-old male patient who presented with traumatic brain injury (TBI) causing left temporal extradural hematoma (EDH). EDH was managed conservatively. The patient had addiction to alcohol, tobacco smoking, paan (containing betel nuts), and some other addictive substances, details of which were not available. The patient's Glasgow Coma Scale (GCS) and serum sodium were normal at admission. On the 7th and 8th days, serum sodium was 107 and 101 milliequivalent/liter (meq/l), respectively, but GCS was normal. Slow infusion of 3% sodium chloride 100 ml was given on the 7th day and 200 ml on the 8th day. However, serum sodium was raised to 128 meq/l on the 10th day. On the 11th day, GCS was deteriorated and the patient developed quadriparesis. Magnetic resonance imaging (MRI) scan showed bilateral symmetrical basal ganglia T2-weighted hyperintensities suggestive of EPM. In severe hyponatremic patient, it is the rapid rise of serum sodium level which causes EPM. Rapid rise of serum sodium can occur even if hyponatremia was corrected with gradual addition of sodium. Consumption of alcohol and addictive substances contributed along with hyponatremia correction, to the development of EPM. Early detection of hyponatremia is the paramount factor in TBI to prevent the debilitating disease of EPM. MRI plays a crucial role in definite diagnosis of EPM.
Keywords: Central pontine myelinolysis, extradural hematoma, extrapontine myelinolysis, Glasgow Coma Scale, hyponatremia, sodium
|How to cite this article:|
Thavara BD, Veettil HP. Hyponatremia correction causing extrapontine myelinolysis. BLDE Univ J Health Sci 2019;4:34-8
Extrapontine myelinolysis (EPM) and central pontine myelinolysis constitute osmotic demyelination syndrome (ODS). Osmotic disturbances and their correction lead to myelin injury causing ODS. Brain lesions are bilaterally symmetrical and constant in location in central pontine myelinolysis (CPM), which is a feature of metabolic or toxic diseases. It is more common in malnourished and alcoholic patients. Rapid rise in serum tonicity in patients with chronic severe hyponatremia will lead to ODS. Zunga et al. presented a case of isolated EPM, in which magnetic resonance imaging (MRI) showed high signal intensity in the bilateral basal ganglia. There are no trials on the treatment. At present, only supportive treatment can be recommended with certainty.
Chang et al. demonstrated that traumatic brain injury (TBI) frequently causes dysregulation of the neuroendocrine system. In TBI, syndrome of inappropriate antidiuretic hormone secretion causes hyponatremia due to pituitary dysfunction.
| Case Report|| |
A 25-year-old male presented with a history of accidental fall from 12-feet height. The patient presented with loss of consciousness, followed by headache and vomiting during admission. The patient was an alcoholic and tobacco smoker. There was a history of addiction to consumption of paan (containing betel nuts) and some other addictive substances, details of which were not available. The correct duration and frequency of consumption of these substances were not known to the relatives. On examination, the patient was conscious and oriented with normal Glasgow Coma Scale (GCS). Cranial nerve examination, motor system, sensory system, reflexes, and cerebellar examination were found to be normal.
Computed tomography (CT) scan showed left anterior temporal extradural hematoma (EDH), left temporal bone linear fracture, and left zygomatic arch fracture [Figure 1]. Serum sodium (Na) was 140 milliequivalent/liter (meq/l) and serum potassium (K) was 4.1 meq/l. Head injury was treated conservatively with antiepileptic medication. The patient was complaining of headache and dizziness. Headache was treated symptomatically with analgesia. On the 7th day, the patient developed recurrent episodes of vomiting and persistent headache. The patient was conscious and oriented, and GCS was normal, but serum Na was 107 meq/l and serum K 3.5 meq/l. Injection 3% sodium chloride (NaCl) 100 ml infusion (containing Na 513 meq/l and Cl 513 meq/l) was given over a period of 6 h, and salt-rich diet was advised. On the 8th day, serum Na was 101 meq/l and serum K was 3 meq/l, but the patient was conscious and oriented, and GCS score was normal. Two doses of injection 3% NaCl 100 ml infusion were given, each over a period of 6 h. Injection potassium chloride (KCl) two ampules infusion (one ampule contains 20 meq each of potassium and chloride) was also given. On the 10th day, serum Na was 128 meq/l and serum K was 3.1 meq/l. Injection KCl two ampules infusion was given. Vomiting frequency had decreased, and GCS was normal. On the 11th day, serum sodium was 135 meq/l and serum potassium was 3.8 meq/l, but GCS was deteriorated to E4V4M5 (E – eye response, V – vocal response, and M – motor response). Serial CT scans showed left temporal EDH of the same size [Figure 2] and [Figure 3]. Following the 11th day onward, serum sodium was maintained above 130 meq/l. The patient was clinically diagnosed as a case of ODS. Along with deteriorated GCS, the patient developed abnormal facial movement with gaze preference to left. Injection sodium valproate 500 mg three times daily was started. A neurologist diagnosed it as an extrapyramidal symptom and started on oral trihexyphenidyl 1 mg three times daily. Injection dexamethasone 2 mg twice daily was started. Electroencephalogram was normal. The patient had developed quadriparesis and hypotonia of all the limbs. Serum calcium and magnesium were normal. On the 22th day, tracheostomy was done to protect the airway and to prevent the respiratory infection. Cerebrospinal fluid study done using lumbar puncture was normal.
|Figure 1: Computed tomography scan taken on the 1st day of trauma showed a left anterior temporal extradural hematoma|
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|Figure 2: Computed tomography scan taken on the 4th day of trauma showed no increase in size of left temporal extradural hematoma|
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|Figure 3: Computed tomography scan taken on the 11th day of trauma showed left temporal subacute extradural hematoma of the same size|
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MRI was done on the 18th day, which showed bilateral symmetrical basal ganglia T2-weighted (T2W) hyperintensity with involvement of caudate nuclei, putamen, and globus pallidus [Figure 4]. Diffusion-weighted imaging showed diffusion-weighted hyperintensities of bilateral basal ganglia [Figure 5]. There was no involvement of the pons and cerebellum. MRI findings were consistent with EPM.
|Figure 4: T2-weighted magnetic resonance imaging scan showed hyperintensities of bilateral basal ganglia|
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|Figure 5: Diffusion-weighted image showed diffusion-weighted hyperintensities of bilateral basal ganglia|
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The patient gradually developed hypertonia of all the limbs. The patient's GCS gradually deteriorated to E4VtM1 (t – tracheostomy) by the 34th day [Table 1]. The patient was on nasogastric tube for feeding and was on urinary catheter. CT scan head taken on the 34th day showed atrophic changes in the brain parenchyma and bilateral basal ganglia hypodensities [Figure 6].
|Table 1: Serial values of serum sodium, serum potassium, and Glasgow Coma Scale following head injury|
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|Figure 6: Computed tomography scan taken on the 34th day showed atrophic changes in the brain parenchyma and bilateral basal ganglia hypodensities|
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During discharge from the hospital on the 67th day, the patient's GCS was E4V2M5, with right-sided weakness (MRC Grade 3). The patient's nurick grade was 5. The patient was discharged with a nasogastric tube for feeding and urinary catheter. Tracheostomy was closed before discharge. After the discharge, the patient was taken to a health center near their home, where physiotherapy, nursing care, and alternate medicine (acupuncture) treatment was given.
The patient was reviewed after 1 year of discharge. His GCS score was E4V2M6. He was not able to speak but makes inappropriate sound. Memory and cognition were impaired. He was able to take self-care with minimal help. He was able to identify his relatives. The patient had improvement in spasticity of the limbs. There was a mild right-sided weakness (MRC Grade 4+), but he was able to walk without support. His Nurick grade was 3.
| Discussion|| |
ODS is a complication of the rapid correction of hyponatremia. It can occur in other conditions which cause rapid changes in osmolality of the interstitial compartment of the brain, which will lead to dehydration of energy-depleted cells with subsequent axonal damage that occurs in characteristic areas. Gradual correction of the hyponatremia and administration of corticosteroids appears to be a major preventive step in ODS patients.
EPM occurs at the junction of gray and white matter. Microscopically, in majority of cases, there is a preservation of axons with degeneration and loss of oligodendrocytes. Serum Na level of >120 mmol/l is called as severe hyponatremia.
Gocht and Colmant, in their autopsy series of 58 cases of ODS, noticed that the demyelinating disease occurred in three subtypes: (1) CPM, (2) CPM combined with EPM, and (3) exclusively EPM. Cerebellum and lateral geniculate body were the most frequently affected extrapontine regions. The lesions were often symmetrical.
Singh et al. performed a systematic review on adult patients with ODS published from 1959 to January 2013. Hyponatremia (78%) was the most common predisposing factor, and encephalopathy (39%) was the most common presentation. Favorable recovery occurred in 51.9% of patients, and death occurred in 24.8% of patients.
Dystonia, mutism, Parkinsonism More Details, and catatonia all have been described in EPM. The movement disorders of EPM represent a treatable manifestation of the ODS in that a symptomatic improvement can occur with dopaminergic treatment in those with parkinsonian features.
Cheng et al. reviewed the medical records of all known psychogenic water drinkers (34) in their hospital from 1977 to 1989. In their study, there was no clinical or radiologic evidence of adverse neurologic sequelae following rapid correction of hyponatremia. All patients recovered immediately after treatment.
Menger and Jörg, in their findings in 44 patients (42 of whom were chronic alcoholics) with CPM, showed that the outcome does not depend on the severity of neurological deficits during the acute phase of the condition or on concomitant internal diseases, including the degree of hyponatremia. They concluded that patients with cerebral myelinolysis survive if the nonspecific secondary complications can be avoided.
EPM may occur despite a treatment of hyponatremia conducted according to published guidelines. Treatment should be extremely cautious when hyponatremia is lasting for more than 48 h.
In our case of severe hyponatremia following head injury, serum Na level was rapidly increased even though Na supplementation was gradually administered in low doses. MRI showed bilaterally symmetrical basal ganglia T2W hyperintensities suggestive of EPM. Consumption of alcohol and addictive substances contributed along with hyponatremia correction, to the development of EPM. The cause for the development of atrophic brain changes in the CT scan taken on the 34th day needs further evaluation with more number of similar cases.
| Conclusions|| |
Even though EPM is rare, any case of severe hyponatremia should be treated with high index of suspicion. In severe hyponatremic patient, it is the rapid rise of serum sodium level which causes EPM. Rapid rise of serum sodium can occur even if hyponatremia was corrected with gradual addition of sodium. Consumption of alcohol and addictive substances contributed along with hyponatremia correction, to the development of EPM. In TBI, early detection of hyponatremia and prevention of development of severe hyponatremia are the paramount factors in the prevention of EPM. MRI plays a crucial role in definite diagnosis of EPM.
The study was done with the support from the Department of Neurosurgery, Government Medical College, Thrissur - 680 596, Kerala, India.
Declaration of patient consent
The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.
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Conflicts of interest
There are no conflicts of interest.
| References|| |
Alleman AM. Osmotic demyelination syndrome: Central pontine myelinolysis and extrapontine myelinolysis. Semin Ultrasound CT MR 2014;35:153-9.
Adams RD, Victor M, Mancall EL. Central pontine myelinolysis: A hitherto undescribed disease occurring in alcoholic and malnourished patients. AMA Arch Neurol Psychiatry 1959;81:154-72.
Martin RJ. Central pontine and extrapontine myelinolysis: The osmotic demyelination syndromes. J Neurol Neurosurg Psychiatry 2004;75 Suppl 3:iii22-8.
Zunga PM, Farooq O, Dar MI, Dar IH, Rashid S, Rather AQ, et al
. Extra pontine osmotic demyelination syndrome. Ann Neurosci 2015;22:51-3.
Chang CH, Liao JJ, Chuang CH, Lee CT. Recurrent hyponatremia after traumatic brain injury. Am J Med Sci 2008;335:390-3.
Gocht A, Colmant HJ. Central pontine and extrapontine myelinolysis: A report of 58 cases. Clin Neuropathol 1987;6:262-70.
Singh TD, Fugate JE, Rabinstein AA. Central pontine and extrapontine myelinolysis: A systematic review. Eur J Neurol 2014;21:1443-50.
Cheng JC, Zikos D, Skopicki HA, Peterson DR, Fisher KA. Long-term neurologic outcome in psychogenic water drinkers with severe symptomatic hyponatremia: The effect of rapid correction. Am J Med 1990;88:561-6.
Menger H, Jörg J. Outcome of central pontine and extrapontine myelinolysis (n=44). J Neurol 1999;246:700-5.
Koenig M, Camdessanché JP, Duband S, Charmion S, Antoine JC, Cathébras P, et al
. Extrapontine myelinolysis of favorable outcome in a patient with autoimmune polyglandular syndrome. Rev Med Interne 2005;26:65-8.
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