No abstract

Cerebral autosomal recessive arteriopathy with subcortical infarcts and leukoencephalopathy (CARASIL) is clinically characterized by early-onset dementia, stroke, spondylosis deformans, and alopecia. In CARASIL cases, brain magnetic resonance imaging reveals severe white matter hyperintensities (WMHs), lacunar infarctions, and microbleeds. CARASIL is caused by a homozygous mutation in high-temperature requirement A serine peptidase 1 (HTRA1). Recently, it was reported that several heterozygous mutations in HTRA1 also cause cerebral small vessel disease (CSVD). Although patients with heterozygous HTRA1-related CSVD (symptomatic carriers) are reported to have a milder form of CARASIL, little is known about the clinical and genetic differences between the two diseases. Given this gap in the literature, we collected clinical information on HTRA1-related CSVD from a review of the literature to help clarify the differences between symptomatic carriers and CARASIL and the features of both diseases. Forty-six symptomatic carriers and 28 patients with CARASIL were investigated. Twenty-eight mutations in symptomatic carriers and 22 mutations in CARASIL were identified. Missense mutations in symptomatic carriers are more frequently identified in the linker or loop 3 (L3)/loop D (LD) domains, which are critical sites in activating protease activity. The ages at onset of neurological symptoms/signs were significantly higher in symptomatic carriers than in CARASIL, and the frequency of characteristic extraneurological findings and confluent WMHs were significantly higher in CARASIL than in symptomatic carriers. As previously reported, heterozygous HTRA1-related CSVD has a milder clinical presentation of CARASIL. It seems that Uemura et al. CSVD Caused by HTRA1 Mutation haploinsufficiency can cause CSVD among symptomatic carriers according to the several patients with heterozygous nonsense/frameshift mutations. However, the differing locations of mutations found in the two diseases indicate that distinct molecular mechanisms influence the development of CSVD in patients with HTRA1-related CSVD. These findings further support continued careful examination of the pathogenicity of mutations located outside the linker or LD/L3 domain in symptomatic carriers.

(Headache 2012;52:822‐824)

Guillain-Barré syndrome (GBS) typically occurs after gastroenteritis and respiratory tract infection, but surgery has also been considered one of the triggers. Posterior reversible encephalopathy syndrome (PRES) is a rare complication of GBS. A normotensive female in her 70s presented ascending paralysis and frontal-parieto-occipital subcortical lesions with intermittent hypertension after spinal surgery. Nerve conduction studies revealed demyelinating polyneuropathy. The patient’s brain lesions disappeared with amelioration of hypertension. She was diagnosed with the demyelinating form of GBS and PRES caused by intermittent hypertension. Intravenous immunoglobulin G (IVIG) improved her symptoms without exacerbation of the PRES. Surgery can be a trigger of GBS, and GBS can cause PRES by hypertension and present as central nervous lesions. It is important to treat hypertension before using IVIG when PRES is suspected as a complication of GBS, since the encephalopathy can be exacerbated by IVIG. There may be more undiagnosed cases of the coexistence of GBS and PRES after surgery because surgery itself can also cause PRES. Proper control of blood pressure and confirmation of negative central nervous lesions are required to treat GBS patients with IVIG safely.

BackgroundThis study aimed to clarify the frequency and clinical features of monogenic cerebral small vessel disease (mgCSVD) among patients with adult-onset severe CSVD in Japan.MethodsThis study included patients with adult-onset severe CSVD with an age of onset ≤55 years (group 1) or >55 years and with a positive family history (group 2). After conducting conventional genetic tests forNOTCH3andHTRA1, whole-exome sequencing was performed on undiagnosed patients. Patients were divided into two groups according to the results of the genetic tests: monogenic and undetermined. The clinical and imaging features were compared between the two groups.ResultsGroup 1 and group 2 included 75 and 31 patients, respectively. In total, 30 patients hadNOTCH3mutations, 11 patients hadHTRA1mutations, 6 patients hadABCC6mutations, 1 patient had aTREX1mutation, 1 patient had aCOL4A1mutation and 1 patient had aCOL4A2mutation. The total frequency of mutations inNOTCH3,HTRA1andABCC6was 94.0% in patients with mgCSVD. In group 1, the frequency of a family history of first relatives, hypertension and multiple lacunar infarctions (LIs) differed significantly between the two groups (monogenic vs undetermined; family history of first relatives, 61.0% vs 25.0%, p=0.0015; hypertension, 34.1% vs 63.9%, p=0.0092; multiple LIs, 87.8% vs 63.9%, p=0.0134).ConclusionsMore than 90% of mgCSVDs were diagnosed by screening forNOTCH3,HTRA1andABCC6. The target sequences for these three genes may efficiently diagnose mgCSVD in Japanese patients.