Uremic encephalopathy with isolated brainstem involvement revealed by magnetic resonance image: a case report

Uraemic brainstem encephalopathy mimicking ocular myasthenia: a case report

BACKGROUND

Uraemia causes a generalised encephalopathy as its most common neurological complication. Isolated brainstem uraemic encephalopathy is rare. We report a case of fatigable ptosis and complex ophthalmoplegia in brainstem uraemic encephalopathy.

CASE PRESENTATION

A 22-year-old Sri Lankan man with end stage renal failure presented with acute onset diplopia and drooping of eyelids progressively worsening over one week. The patient had not complied with the prescribed renal replacement therapy which was planned to be initiated 5 months previously. On examination, his Glasgow coma scale score was 15/15, He had a fatigable asymmetrical bilateral ptosis. The ice-pack test was negative. There was a complex ophthalmoplegia with bilateral abduction failure and elevation failure of the right eye. The diplopia did not worsen with prolonged stare. The rest of the neurological examination was normal. Serum creatinine on admission was 21.81 mg/dl. The repetitive nerve stimulation did not show a decremental pattern. Magnetic resonance imaging (MRI) of the brain demonstrated diffuse midbrain and pontine oedema with T2 weighted/FLAIR hyperintensities. The patient was haemodialyzed on alternate days and his neurological deficits completely resolved by the end of the second week of dialysis. The follow up brain MRI done two weeks later demonstrated marked improvement of the brainstem oedema with residual T2 weighted/FLAIR hyperintensities in the midbrain.

CONCLUSIONS

Uraemia may rarely cause an isolated brainstem encephalopathy mimicking ocular myasthenia, which resolves with correction of the uraemia.

Extensive multiregional urea elevations in a case-control study of vascular dementia point toward a novel shared mechanism of disease amongst the age-related dementias

Introduction

Vascular dementia (VaD) is one of the most common causes of dementia among the elderly. Despite this, the molecular basis of VaD remains poorly characterized when compared to other age-related dementias. Pervasive cerebral elevations of urea have recently been reported in several dementias; however, a similar analysis was not yet available for VaD.

Methods

Here, we utilized ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) to measure urea levels from seven brain regions in post-mortem tissue from cases of VaD (n = 10) and controls (n = 8/9). Brain-urea measurements from our previous investigations of several dementias were also used to generate comparisons with VaD.

Results

Elevated urea levels ranging from 2.2- to 2.4-fold-change in VaD cases were identified in six out of the seven regions analysed, which are similar in magnitude to those observed in uremic encephalopathy. Fold-elevation of urea was highest in the basal ganglia and hippocampus (2.4-fold-change), consistent with the observation that these regions are severely affected in VaD.

Discussion

Taken together, these data not only describe a multiregional elevation of brain-urea levels in VaD but also imply the existence of a common urea-mediated disease mechanism that is now known to be present in at least four of the main age-related dementias.

Case report: MRI findings of acute uremic encephalopathy in a 1-year-old boy

We present a 1-year-old boy who presented to the emergency department with a 7-day history of diarrhoea and vomiting. The initial renal function profile demonstrated a urea of 55 mmol l⁻¹ (normal range between 5 and 20 mmol l⁻¹), creatinine 695 micromol/L (normal range between 62–106 micromol/L) and potassium 9.1 mmol l⁻¹ (normal range between 3.5–5.0 mmol l⁻¹), with a profound metabolic acidosis. Upon examination, there were no significant findings, specifically no neurological abnormality.

He was prescribed back-to-back Salbutamol nebulisers, to increase the shift of extracellular potassium into the intracellular space, followed by i.v. calcium gluconate, with some improvement in potassium levels. A further 5 mmol of sodium bicarbonate was given, as well as a stat dose of 1 mg/kg furosemide, and per rectal calcium resonium. He was then commenced on an infusion with 10% dextrose with insulin.

He was subsequently found to be in urinary retention and a catheter was inserted, which drained 1700 ml.

A subsequent renal function profile, 24 hours after admission, demonstrated improvement with urea 39 mmol l⁻¹, creatinine 300 micromol/L and potassium 3.0 mEq/L.

Isolated brainstem involvement in posterior reversible encephalopathy syndrome: a case report and review of the literature

Posterior reversible encephalopathy syndrome (PRES) is a clinical-radiological syndrome, reversible vasogenic edema predominantly within parieto-occipital regions. However, isolated brainstem involvement in PRES has been rarely reported, little is known about its clinical manifestations, radiological features and outcomes. We reported a case with PRES with only brainstem involvement and performed a systematic review of published cases. Twenty-four cases, together with our case, were included in the analysis. Mean age was 43 years and 63% were males. Hypertension (50%), nephropathy (25%) and chemotherapy (21%) were the major risk factors. All patients except two had acute hypertension and 50% of patients had renal dysfunction at onset. The most common symptoms were altered consciousness (46%) and headache (46%), Seizure was only presented in 21% of patients. All patients except two were treated with antihypertension. Most patients recovered to their neurological baseline. Clinicians should recognize this unique variant finding in PRES. which always affects males with severe hypertension, especially combined with renal dysfunction. Antihypertensive treatment is the most widely used therapy. Outcome is usually well.

Isolated pan-pontine posterior reversible encephalopathy syndrome in a patient with uncontrolled hypertension

Recognition of central variant PRES is key to avoiding detrimental treatment. The pons may be the most vulnerable area in central PRES, and delayed presentation may result in greater damage. CSF reporting may lead to eventual recognition of a common profile, and possible aid in future diagnosis.