Atypical reversible posterior leukoencephalopathy syndrome in thrombotic thrombocytopenic purpura

Cerebral vascular injury in transplant-associated thrombotic microangiopathy

Transplant-associated thrombotic microangiopathy (TA-TMA) and atypical hemolytic uremic syndrome (aHUS) are complement-mediated TMAs. The central nervous system (CNS) is the most common extrarenal organ affected by aHUS, and, despite mechanistic overlap between aHUS and TA-TMA, CNS involvement is rarely reported in TA-TMA, suggesting that CNS involvement in TA-TMA may be underdiagnosed and that these patients may benefit from complement blockers. In addition, there are no widely used histologic or radiologic criteria for the diagnosis of TMA in the brain. Thirteen recipients of pediatric hematopoietic cell transplants (HCTs) who had TA-TMA and who underwent autopsy were studied. Seven of 13 brains had vascular injury, and 2 had severe vascular injury. Neurologic symptoms correlated with severe vascular injury. Classic TMA histology was present and most often observed in the cerebellum, brainstem, and cerebral white matter. Abnormalities in similar anatomic regions were seen on imaging. Brain imaging findings related to TMA included hemorrhages, siderosis, and posterior reversible encephalopathy syndrome. We then studied 100 consecutive HCT recipients to identify differences in neurologic complications between patients with and those without TA-TMA. Patients with TA-TMA were significantly more likely to have a clinical concern for seizure, have an electroencephalogram performed, and develop altered mental status. In summary, our study confirms that TA-TMA involves the brains of recipients of HCT and is associated with an increased incidence of neurologic symptoms. Based on these findings, we propose that patients with low- or moderate-risk TA-TMA who develop neurologic complications should be considered for TA-TMA-directed therapy.

Fatal Thrombotic Microangiopathy and Posterior Reversible Encephalopathy Syndrome in a Patient with Anti-melanoma Differentiation-associated Gene 5 Antibody-positive Dermatomyositis

A 56-year-old woman presented with dermatomyositis positive for anti-melanoma differentiation-associated gene 5 antibody. No interstitial lung disease was detected. Despite treatment with methylprednisolone pulse therapy and cyclosporine, dysphagia developed. Furthermore, the presence of thrombocytopenia, elevated lactate dehydrogenase levels, and an undetectable haptoglobin level suggested the possibility of thrombotic microangiopathy (TMA). Disturbed consciousness developed shortly after TMA onset, and brain magnetic resonance imaging revealed hyperintensity lesions in the bilateral basal ganglia, thalami, and brainstem. The patient was diagnosed with atypical posterior leukoencephalopathy syndrome before dying of heart failure later that day. In conclusion, early TMA recognition and prompt intensive treatment are critical in such cases.

An adult case of atypical hemolytic uremic syndrome presented with posterior reversible encephalopathy syndrome: Successful response to late-onset eculizumab treatment

Atypical hemolytic uremic syndrome is a rare and progressive disease caused by uncontrolled alternative complement activation. Dysregulatıon of the complement activation results in thrombotic microangiopathy and multiorgan damage. A 29-yearold woman who was admitted with complaints of vomiting and headache was detected to have acute renal failure with microangiopathic hemolytic anemia (MAHA). After the diagnosis of atypical hemolytic uremic syndrome (aHUS), she was treated with plasma exchange (PE) and hemodialysis (HD). She has experienced hypertensionrelated posterior reversible encephalopathy syndrome (PRES) at the second plasma exchange. She was initiated on eculizumab therapy because of no response to PE on the 34^th days. Her renal functions progressively improved with eculizumab treatment. Dependence on dialysis was over by the 4^th month. Dialysis free-serum Creatinine level was 2.2 mg/dL [glomerular filtration rate (e-GFR): 30 mL/min/1.73 m²] after 24 months.

Neurological involvement (PRES, etc.) is the most common extrarenal complication and a major cause of mortality and morbidity from aHUS. More importantly, we showed that renal recovery may be obtained following late-onset eculizumab treatment in patient with aHUS after a long dependence on hemodialysis.

Uncommon Causes of Cerebral Microbleeds

BACKGROUND

Cerebral microbleeds (CMBs) are small and round perivascular hemosiderin depositions detectable by gradient echo sequences or susceptibility-weighted imaging. Cerebral microbleeds are common among patients with hypertension, cerebral ischemia, or cerebral amyloid angiopathy. In this article, we describe uncommon causes of CMBs.

METHODS

We searched Pubmed with the keyword CMBs for relevant studies and looked for different uncommon causes of CMBs.

RESULTS

CMBs have several uncommon etiologies including posterior reversible encephalopathy syndrome, infective endocarditis, brain radiation therapy, cocaine abuse, thrombotic thrombocytopenic purpura, traumatic brain injury, intravascular lymphomatosis or proliferating angio-endotheliomatosis, moyamoya disease, sickle cell anemia/β-thalassemia, cerebral autosomal dominant arteriopathy subcortical infarcts, and leukoencephalopathy (CADASIL), genetic syndromes, or obstructive sleep apnea.

CONCLUSIONS

Understanding the uncommon causes of CMBs is not only helpful in diagnosis and prognosis of some of these rare diseases, but can also help in better understanding different pathophysiology involved in the development of CMBs.

Thrombotic thrombocytopenic purpura with concomitant small- and large-vessel thrombosis, atypical posterior reversible encephalopathy syndrome and cerebral microbleeds

We report a case of thrombotic thrombocytopenic purpura (TTP) with uncommon imaging features, namely concomitant small- and large-vessel thrombosis, atypical locations of posterior reversible encephalopathy syndrome (PRES) and microbleeds. A 58-year-old Chinese woman presented with slurred speech and multiple petechiae over lower limbs. Blood tests showed thrombocytopenia. Neuroimaging showed multiple acute small infarcts and PRES in the subcortical white matter, basal ganglia, thalamus, brainstem and occipital lobe. Microbleeds were noted. She was treated as TTP with infusion of cryo-reduced plasma (CRP). Patient subsequently developed dense right hemiplegia. Computed tomography of brain demonstrated a new major left middle cerebral artery territory infarct. She was stabilized after 2 weeks of treatment with daily CRP infusion, then received rehabilitation for major stroke. Early recognition of TTP provides the best chance of recovery as most lesions are reversible when TTP was treated. However, concurrent large artery thrombosis could cause major morbidity and mortality.

Acute neurological symptoms of Moschcowitz disease - case report

Thrombotic thrombocytopenic purpura (TTP, Moschcowitz disease) is characterized by thrombotic microangiopathy leading to microvascular occlusion and ischemic dysfunction of various organs including the brain. In the course of the rare disease most patients develop neurological symptoms of varying severity and characteristics. The case presented is that of a 34-year-old female patient with profound thrombocytopenia, anemia and rapidly progressive neurological deterioration into coma with normal result of brain imaging. TTP was recognized on the basis of hematological analysis. The initiated steroid therapy and plasma exchange failed to prevent the turbulent course of disease in the patient, who died exhibiting symptoms of multiple organ failure caused by thrombotic microangiopathy. TTP remains to be a diagnostic challenge, particularly in the case of atypical symptoms or when neuroimaging and laboratory results are inconclusive. Before using the corticosteroids and plasma exchange, TTP had a case fatality rate of approx. 90% (Podolak-Dawidziak, 2013). Nowadays recovery is possible when vigorous treatment is introduced early in the course of this disease.

Diabetic uremic syndrome studied with cerebral MR spectroscopy and CT perfusion

Diabetic uremic syndrome (DUS) is an increasingly reported acute neurometabolic cerebral disease with characteristic clinical and imaging features. Clinical spectrum includes a wide range of movement disorders such as acute parkinsonism. Imaging studies show reversible (with hemodialysis) bilateral lesions in the lenticular nuclei. DUS pathophysiology has not been entirely clarified yet. Our case study shows certainly that LN lesions are characterized with increased lactate peak with MR spectroscopy and decreased perfusion in computerized tomography perfusion along with increased diffusion with apparent diffusion coefficient (ADC) mapping in the subacute phase of the syndrome. Abnormalities were almost normalized quickly after metabolic control by hemodialysis. Together with reports indicating that a deficit of glucose use exacerbated with acute increase of uremic toxins in bilateral LN, observed changes (lactate peak and hypoperfusion) led us to state that a primary metabolic depression may cause this syndrome. Metabolic depression is probably due to uncompensated uremic toxin accumulation related mitochondrial supression and/or dysfunction. This definition fits well to the other elements of DUS such as ADC evolution and marked lesion regression. Our single case study is not supportive of other previously credited mechanisms such as microvascular dysfunction related focal ischemia or hypoperfusion, prolonged uremic toxin related histotoxic hypoxia, central pontine myelinolysis-like demyelination and posterior leukoencephalopathy spectrum disorder related vasogenic edema.

Reversible posterior leukoencephalopathy syndrome in a patient with thrombotic thrombocytopenic purpura

Thrombotic thrombocytopenic purpura (TTP) is an autoimmune disorder characterised by fever, microangiopathic haemolytic anaemia, renal insufficiency, and thrombocytopenia. Neurological involvement, a prominent component of TTP, is characterised by a variety of brain lesions which include reversible cerebral oedema or magnetic resonance imaging (MRI) features of reversible posterior leukoencephalopathy syndrome (RPLS). TTP is frequently associated with deficiency of the von Willebrand factor-cleaving protease, ADAMTS13.Here, we report a case of TTP with severe acute encephalopathy. Posterior leukoencephalopathy and brainstem oedema with triventricular hydrocephalus were observed on MRI. The low activity of ADAMTS13 was not observed and ADAMTS-13 antibodies were absent. Neurological symptoms and patient's condition were completely resolved by plasma exchange therapy in addition to high dose of methylprednisolone.

Neurological involvement in a child with atypical hemolytic uremic syndrome

We report the case of a 4-year-old boy, diagnosed with atypical hemolytic uremic syndrome (HUS) due to a hybrid factor H. He progressed to end-stage renal failure despite plasmatherapy and underwent bilateral nephrectomy because of uncontrolled hypertension. Three days after, he had partial complex seizures with normal blood pressure, normal blood count and normal magnetic resonance imaging (MRI), which recurred 1 month later. Eight months later, he had a third episode of seizures, with hemoglobin of 10 g/dl without schizocytes, low haptoglobin of 0.18 g/l, and moderate thrombocytopenia (platelets 98 × 10(9)/l). He remained hypertensive and deeply confused for 2 days. The third MRI showed bilateral symmetrical hyperintensities of the cerebral pedunculas, caudate nuclei, putamens, thalami, hippocampi, and insulae suggesting thrombotic microangiopathy secondary to a relapse of HUS rather than reversible posterior leukoencephalopathy syndrome (RPLS), usually occipital and asymmetrical. Plasmatherapy led to a complete neurological recovery within 2 days although hypertension had remained uncontrolled. The fourth MRI 10 weeks after, on maintenance plasmatherapy, was normal and clinical examination remained normal, except for high blood pressure. In conclusion, brain MRI allows differentiating thrombotic microangiopathy lesions from RPLS in atypical HUS, which is crucial since lesions may be reversible with plasmatherapy.

Coma in thrombotic thrombocytopenic purpura

Thrombotic thrombocytopenic purpura (TTP) is characterised by a thrombotic, haemolytic microangiopathy leading to microvascular occlusion, haemolysis and ischaemic dysfunction of various organs including the brain. TTP may present with a variety of neurological symptoms, including headache, focal deficits, seizures and coma. The authors describe a 55-year-old man presenting with abdominal pain and rapidly progressive deterioration into coma without focal neurological deficits or seizures. A concomitant, transient, rapid increase in blood pressure raised the suspicion of a hypertensive crisis. Yet, our patient did not improve after vigorous treatment with antihypertensives. Brain imaging excluded a hypertensive leucoencephalopathy. Despite the absence of a disintegrin and metalloproteinase with a thrombospondin type 1 motif member 13 (ADAMTS13) deficiency, the diagnosis idiopathic TTP was made after excluding secondary causes of TTP. Upon treatment with plasma exchange, corticosteroids and vincristin our patient gradually improved. On discharge to a rehabilitation centre he was awake and alert, had minor cognitive deficits and a mild proximal tetraparesis consistent with a critical illness poly(neuro)myopathy.