INTRODUCTION

Gayet-Wernicke’s encephalopathy is an acute neurological complication secondary to thiamine deficiency (vitamin B1). It is frequently encountered in heavy drinkers, but can sometimes be found in other circumstances. We report a case of Gayet-Wernicke’s encephalopathy complicating incoercible vomiting on hyperemesis gravidarum. 

A CLINICAL CASE 

Mrs. Amina B. is a 25-year-old female at 27 weeks of pregnancy consulting in the eEmergency Department for deep asthenia and the inability to walk and stand up. 

She is a patient with no specific pathological history, G2P1, hospitalized during the first trimester of pregnancy in the Gynecology Department for severe vomiting with severe ionic disorders and outgoing under iron one month ago. 

The clinical examination shows an emaciation of more than 10 kg since the beginning of pregnancy with a mucous skin pallor, a slight confusion, horizontal nystagmus and fluctuating diplopia, with cerebellar ataxia and net dysmetry as well as hypotonia of leg muscles with falling feet and steppage without sensory deficit. Biology showed hypoglycemia (Gly 4.1 mmol / L), iron deficiency anemia (Hb 9.6 g / dlVGM 88.3 FL TCMH 29.9 pg) and transaminases 2 times the normal. The rest was normal.

The diagnosis of Gayet’s and Wernicke’s encephalopathy was then mentioned, a parenteral supplementation with thiamine in charge dose (1g) and then in daily intake (500mg) was immediately introduced. Confirmed by a low dosage of vitamin B1 at 64nmol / l (N: 76nmol-185nmol) therapeutic management and exploration were completed in the Neurology Department with a normalized MRI and an electromyogram showing ssensitivo-motor distal abnormalities. 

The young woman led her pregnancy to term and gave birth to a healthy child and the evolution under thiamine at the dose of 300mg per os per day was favorable with a gradual regression of ataxia and a complete disappearance of other disorders. 

Gayet-Wernicke’s encephalopathy is an acute neuropsychiatric complication due to vitamin B1 deficiency (thiamine). It was first described in 1881 by Carl Wernicke. It is a rare disease. The autopsy prevalence estimated at 0.8-2.8% is much higher than that observed with clinical manifestations (0.04 - 0.13%) [1]. vitamin B1 is present in the diet. Daily requirements are in the order of 1.4 mg / day and are increased by a high-calorie or high-carbohydrate diet. 

Absorption is performed at the duodenum level and the passage of the blood-brain barrier is active and mostly passive as a function of the concentration gradient. Its active biological form is thiamine pyrophosphate, which is an essential coenzyme of several biochemical reactions in the brain [1]. Thiamine deficiency leads to cerebral damage, lesions of varying severity, ranging from hemorrhagic sufferings to destruction of neurons. Gayet-Wernicke’s encephalopathy is more commonly observed in chronic alcoholism, but more generally in a context of severe malnutrition. For example, pregnancy vomiting, prolonged parenteral nutrition, hunger strike, gastrointestinal tumors, cancers and chemotherapy [2], digestive surgery, pyloric stenosis, chronic renal failure at the final stage and anorexia nervosa. Concerning our patient, incoercible vomiting lasted 2 months, denutrition and secondary ionic disorders led to hospitalization in gynecological service where a sugary diet without vitamin supplementation was prescribed which rapidly increased the risk of the onset of the disease, encephalopathy. 

This rapid decompensation is due to the sudden consumption of the last bodily reserves of thiamine during the supply of sweet solutes alone. Thiamine deficiency results in brain damage in 2 to 3 weeks [4], the time required to deplete B1 stocks in the body being 18 days. The onset of clinical signs is on average of 4 weeks. In our patient’s case, a month elapsed between leaving hospital and consultation in emergencies, but her neurological signs (vertigo and asthenia) had begun long before and the patient put them on the account of pregnancy.

The diagnosis is clinical but the triad associating ophthalmoplegia, mental confusion and ataxia, present in our patient, is found only in 10% of cases [5]. In 19% of patients, none of these was found [6. A non-specific confusional state is most often encountered with other clinical signs such as cognitive disorders, somnolence, stuporous state or coma, which can be found in 80% of patients. Differential diagnosis in some cases may be difficult with acute alcohol poisoning or withdrawal syndrome. The same is true in the post-operative period when complications may mask the picture or precipitate it.

Metastasis or a brain tumor, ischemic stroke or haemorrhagic stroke can also simulate the picture. For some authors, diagnosis is very likely when two of the following four conditions are present: malnutrition, oculomotor disorders, cerebellar disorders, impairment of mental state or even moderate memory impairment7].In the presence of a suspicion of Gayet-Wernicke encephalopathy, MRI is the reference examination [8]. Its sensitivity and speci!city are respectively 53% and 93% [9]. It shows hypersignals in T2, FLAIR and di#usion, typical of their localization and symmetrical character around the aqueduct of Sylvius, the third ventricle and especially at the level of the mamillary tubercles [8]. Normal imaging does not eliminate the diagnosis.

thy can be confirmed by the determination of the blood concentration of thiamine or its phosphate derivatives (monophosphate or diphosphate). Normal levels range from 60 to 220 nmol / l in adults. In the case of our patient, vomiting decreased significantly after leaving the Gynecology Department, so the minimal intake of thiamine through the patient’s poor diet could explain normal imaging and the thiamine level at 64 nmol / l.

Gayet-Wernicke’s encephalopathy is a medical emergency. Treatment should be started early as soon as the diagnosis is suspected and should not be delayed by vitamin B dosage. There is no consensus on the amount of thiamine to be delivered, the duration of treatment and the number of doses administered per day. 

However, the European Federation of Neurological Societies recommends that thiamine be administered 200 mg three times daily, preferably intravenously before glucose is administered and normal diet is resumed [9]. Treatment should be continued for some patients until vomiting is stopped and normal diet is resumed [11], and for others until the end of pregnancy [2, 8]. Our patient received 500 mg / day of vitamin B1 injectable for seven days with a good progression and an oral relay providing 500 mg of thiamine per day. 

The prognosis of Gayet-Wernicke’s encephalopathy is extremely variable. It is favorable when the disease is diagnosed early with an adequate treatment and a marked improvement in symptoms, as observed in the case of our patient. Only 16% of inadequately treated patients recover completely. Mortality rate is 17-20%. 

CONCLUSION 

Gayet-Wernicke’s encephalopathy is a rare disease. Faced with a risk situation, the triad ophthalmoplegia, mental confusion and ataxia is evocative. The MRI is the reference examination and the vitamin dosage will be done if necessary and possible. Early treatment allows for a favorable outcome and avoids complications and death.