Acute Wernicke's encephalopathy associated with hyperemesis gravidarum: magnetic resonance imaging findings

Magnetic Resonance Imaging in a Case of Wernicke's Encephalopathy with Hyperemesis Gravidarum

We describe a 29-year-old pregnant woman presenting with neurological signs and diagnosed to have Wernicke's encephalopathy. The patient had a full recovery after prompt intravenous thiamine therapy. The clinical, pathological and MR features of Wernicke's encephalopathy are discussed.

Hyperemesis gravidarum complicated by Wernicke encephalopathy: background, case report, and review of the literature

Wernicke encephalopathy (WE) is a rare but known complication of severe hyperemesis gravidarum caused by thiamine deficiency. This article presents an unusual case that occurred at our institution and reviews the 48 previously published cases of WE in pregnancy. Considering all the 49 cases, the mean (+/-standard deviation) patients' age was 26.7 +/- 4.9 years, the mean gestational age when WE manifested was 14.3 +/- 3.4 weeks, and the mean duration of vomiting and feeding difficulties was 7.7 +/- 2.8 weeks. Wernicke's classic triad (confusion, ocular abnormalities, and ataxia) manifested in only 46.9% (23 of 49) of the patients. Confusion affected 63.3% (31 of 49) of the patients, ocular signs 95.9% (47 of 49) and symptoms 57.1% (28 of 49), and ataxia 81.6% (40 of 49). Deterioration of consciousness affected 53.1% (26 of 49) of the subjects and memory impairment 61.2% (30 of 49). Complete remission of the disease occurred in only 14 of 49 cases. Symptom resolution required months and permanent impairments were common. The overall pregnancy loss rate, directly (spontaneous fetal loss) and indirectly (planned abortion) attributable to WE, was 47.9% (23 of 49). The diagnosis of WE is clinical and can be rapidly confirmed by magnetic resonance imaging. We emphasize the importance of thiamine supplementation to women with prolonged vomiting in pregnancy, especially before intravenous or parenteral nutrition. We also underline the necessity to promptly replace vitamin B1 when neurologic symptoms and/or signs develop in a patient with hyperemesis gravidarum.

Wernicke's encephalopathy with hyperemesis and ketoacidosis

BACKGROUND

Avitaminosis can result from the acute malnutrition associated with prolonged pregnancy-related hyperemesis. Serious complications may arise from thiamine deficiency under these circumstances.

CASE

We review the relevant literature and describe a case with central nervous system involvement presenting with typical manifestations of Wernicke's encephalopathy, apparently precipitated by a combination of hyperemesis gravidarum, diabetic ketoacidosis, and intravenous glucose administration.

CONCLUSION

While this life-threatening complication is rare, it is important for all who care for obstetric patients to be aware of it and alert to its development. Early recognition is critical given the need to treat affected women expeditiously to help avoid potentially fatal adverse consequences. Prophylactic thiamine supplementation should be considered in the care of gravidas with hyperemesis.

Depletion of brain histamine produces regionally selective protection against thiamine deficiency-induced lesions in the rat

Breakdown of the blood brain barrier and the subsequent accumulation of free radicals, lactate, and glutamate appear to be the immediate causes of thiamine deficiency (TD)-induced damage to thalamus. The mechanisms triggering these events are unknown but recent evidence suggests an important role of histamine. We therefore studied the effects of histamine depletion on thalamic lesions in the pyrithiamine-induced thiamine deficient (PTD) rat. Chronic intracerebroventricular (i.c.v., 7 days) infusion of alpha-fluoromethylhistidine (FMH), combined with bilateral ibotenate destruction of the histamine-containing neurons in the tuberomammillary (TM) nucleus and bolus i.c.v. infusion of 48/80, a potent mast cell degranulating agent, was used to deplete brain histamine levels. PTD rats receiving combined FMH + 48/80 + TM lesions developed acute neurological symptoms, including spontaneous seizures, approximately 1 day earlier than PTD rats treated with i.c.v. infusion of vehicle and sham lesions of the TM. When examined 1 week after restoration of thiamine, the PTD vehicle + sham lesion animals contained severe neuronal loss and gliosis in midline, intralaminar, ventral, lateral, and posterior nuclei. PTD animals treated with FMH + 48/80 + TM lesions had little evidence of neuronal loss or microglial proliferation in thalamus except in the gelatinosus and anteroventral nuclei, in which there was complete neuronal loss. These data demonstrate a significant and regionally selective role of histamine in the development of thalamic lesions in a rat model of Wernicke's encephalopathy. Furthermore, these data suggest either a dissociation between seizures and thalamic lesions or a significant role of histamine in seizure-related damage to the thalamus.

Wernicke's encephalopathy due to hyperemesis gravidarum: an under-recognised condition

We present a case of a 25-year-old woman with drowsiness, nystagmus, severe ataxia and areflexia, which developed six weeks after admission to an obstetric clinic for hyperemesis gravidarum. She had been treated with intravenous dextrose and electrolyte solutions and antiemetics. Magnetic resonance imaging (MRI) performed on the fifth day of her neurologic symptoms showed increased intensity in both thalami, periaqueductal grey matter, the floor of the fourth ventricle and superior cerebellar vermis in T2 weighted and FLAIR images. Clinical signs and MRI findings were consistent with the diagnosis of Wernicke's encephalopathy. On the third day of thiamine replacement, neurologic signs improved dramatically In addition to our case, we review 29 previously reported cases of Wernicke's encephalopathy associated with hyperemesis gravidarum, and emphasize the importance of thiamine supplementation to women with prolonged vomiting in pregnancy especially if they are given intravenous or parenteral nutrition.

Wernicke's encephalopathy following gastroplasty for morbid obesity

BACKGROUND

The syndrome of Wernicke's encephalopathy consists of two of four features of (1) dietary deficiency; (2) oculomotor abnormality; (3) cerebellar dysfunction; and (4) confusion or mild memory impairment. Predisposing risk factors include alcoholism, hyperemesis gravidarum and prolonged intravenous feeding.

METHODS

A 35-year-old female developed refractory emesis, severe weight loss, and hypokalemia following banded gastroplasty for morbid obesity. Reversal of gastroplasty was performed four months following initial surgery. Following reversal, the patient developed confusion, ataxia, leg weakness and nystagmus.

RESULTS

Examination of the patient demonstrated disorientation with confusion, vertical nystagmus worse on downgaze, diffuse weakness of the lower extremities, and bilateral dysmetria. Magnetic resonance imaging of the brain demonstrated symmetrical areas of increased T2 signal present bilaterally in the medial thalamic nuclei. The patient did not demonstrate any initial improvement with intravenous thiamine but improved over two months of follow-up.

CONCLUSION

Wernicke's encephalopathy has been reported in the European literature as a complication of gastroplasty, with rare recognition of this clinical entity in the North American literature. This potential complication of gastroplasty may be preventable by nutritional intervention in subjects experiencing severe weight loss and emesis following surgery.