A case report of reversible cerebral vasoconstriction syndrome with thunderclap headache significantly exacerbated in the supine position and alleviated in the standing position.

BACKGROUND: Reversible cerebral vasoconstriction syndrome (RCVS) is characterized by sudden onset thunderclap headache and multiple segmental reversible cerebral vasoconstrictions that improve within 3 months. The postpartum period is a well-known precipitating factor for the onset of RCVS. Cerebral venous thrombosis (CVT) causes thunderclap headaches in the postpartum period. While headache in CVT is sometimes exacerbated in the supine position, the severity of the headache in RCVS is usually independent of body position. In this study, we report a case of RCVS with thunderclap headache exacerbated in the supine position, and headache attacks that resolved quickly in the standing position during the postpartum period. CASE PRESENTATION: A 33-year-old woman presented with a sudden increase in blood pressure and thunderclap headache on the fifth postpartum day (day 1: the first sick day). The headache was severe and pulsatile, with onset in the supine position in bed, and peaked at approximately 10 s. It was accompanied by nausea and chills but there were no scintillating scotomas or ophthalmic symptoms. The headache resolved in the standing or sitting position but was exacerbated and became unbearable within a few seconds when the patient was in the supine position. Therefore, she was unable to lie supine at night. Computed tomography angiography (CTA) of the head on day 2 and magnetic resonance imaging (MRI) and magnetic resonance angiography (MRA) on day 3 showed no abnormalities. However, considering the possibility of RCVS, verapamil was initiated on day 3. The headache resolved the following day. MRA of the head on day 10 revealed diffuse and segmental stenoses in the bilateral middle and posterior cerebral arteries and basilar artery. Therefore, the patient was diagnosed with RCVS. The headache gradually resolved and disappeared completely on day 42. Cerebral vasoconstriction was also improved on MRA on day 43. CONCLUSIONS: This postpartum RCVS case was notable for the exacerbation of headaches in the supine position. For the diagnosis of thunderclap headache in the postpartum period, RCVS should be considered in addition to CVT when the patient presents with a headache that is exacerbated in the supine position.

TDP-43 differentially propagates to induce antero- and retrograde degeneration in the corticospinal circuits in mouse focal ALS models.

Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disease characterized by TDP-43 inclusions in the cortical and spinal motor neurons. It remains unknown whether and how pathogenic TDP-43 spreads across neural connections to progress degenerative processes in the cortico-spinal motor circuitry. Here we established novel mouse ALS models that initially induced mutant TDP-43 inclusions in specific neuronal or cell types in the motor circuits, and investigated whether TDP-43 and relevant pathological processes spread across neuronal or cellular connections. We first developed ALS models that primarily induced TDP-43 inclusions in the corticospinal neurons, spinal motor neurons, or forelimb skeletal muscle, by using adeno-associated virus (AAV) expressing mutant TDP-43. We found that TDP-43 induced in the corticospinal neurons was transported along the axons anterogradely and transferred to the oligodendrocytes along the corticospinal tract (CST), coinciding with mild axon degeneration. In contrast, TDP-43 introduced in the spinal motor neurons did not spread retrogradely to the cortical or spinal neurons; however, it induced an extreme loss of spinal motor neurons and subsequent degeneration of neighboring spinal neurons, suggesting a degenerative propagation in a retrograde manner in the spinal cord. The intraspinal degeneration further led to severe muscle atrophy. Finally, TDP-43 induced in the skeletal muscle did not propagate pathological events to spinal neurons retrogradely. Our data revealed that mutant TDP-43 spread across neuro-glial connections anterogradely in the corticospinal pathway, whereas it exhibited different retrograde degenerative properties in the spinal circuits. This suggests that pathogenic TDP-43 may induce distinct antero- and retrograde mechanisms of degeneration in the motor system in ALS.

Heterogenous Genetic, Clinical, and Imaging Features in Patients with Neuronal Intranuclear Inclusion Disease Carrying NOTCH2NLC Repeat Expansion.

Neuronal intranuclear inclusion disease (NIID) is a neurodegenerative disorder that is caused by the abnormal expansion of non-coding trinucleotide GGC repeats in NOTCH2NLC. NIID is clinically characterized by a broad spectrum of clinical presentations. To date, the relationship between expanded repeat lengths and clinical phenotype in patients with NIID remains unclear. Thus, we aimed to clarify the genetic and clinical spectrum and their association in patients with NIID. For this purpose, we genetically analyzed Japanese patients with adult-onset NIID with characteristic clinical and neuroimaging findings. Trinucleotide repeat expansions of NOTCH2NLC were examined by repeat-primed and amplicon-length PCR. In addition, long-read sequencing was performed to determine repeat size and sequence. The expanded GGC repeats ranging from 94 to 361 in NOTCH2NLC were found in all 15 patients. Two patients carried biallelic repeat expansions. There were marked heterogenous clinical and imaging features in NIID patients. Patients presenting with cerebellar ataxia or urinary dysfunction had a significantly larger GGC repeat size than those without. This significant association disappeared when these parameters were compared with the total trinucleotide repeat number. ARWMC score was significantly higher in patients who had a non-glycine-type trinucleotide interruption within expanded poly-glycine motifs than in those with a pure poly-glycine expansion. These results suggested that the repeat length and sequence in NOTCH2NLC may partly modify some clinical and imaging features of NIID.

[Disseminated herpes zoster complicated by lumbosacral polyradiculoneuritis and fibular neuropathy: A case report].

A 74-year-old woman who presented with a skin eruption involving the left lateral leg along the L5 dermatome and widespread eruptions on the buttocks and trunk was diagnosed with disseminated herpes zoster (HZ). She also had left lower extremity muscle weakness. The pattern of distribution of muscle weakness and gadolinium-enhanced magnetic resonance imaging findings indicated polyradiculoneuritis mainly affecting the L5 spinal root. Moreover, we observed severe weakness of the left tibialis anterior muscle. Weakness of the other L5 myotomes reduced after antiviral treatment; however, left tibialis anterior muscle weakness persisted. We concluded that lumbosacral polyradiculoneuritis was attributable to varicella-zoster virus (VZV) infection, which also caused fibular neuropathy in this case. Retrograde transport of the VZV may have infected the fibular nerve throughout the sites of skin eruption. It is important to be mindful of simultaneous nerve root and peripheral nerve involvement in cases of motor paralysis associated with HZ infection.

Patients with heterozygous HTRA1-related cerebral small vessel disease misdiagnosed with other diseases: Two case reports.

White matter hyperintensities (WMHs) on brain magnetic resonance (MR) images are characteristic of hereditary cerebral small vessel disease (CSVD), including high-temperature requirement serine peptidase A1 (HTRA1)-related CSVD. Although HTRA1-related CSVD is increasingly recognized, the diagnosis is still challenging. We encountered two patients with HTRA1-related CSVD who were misdiagnosed with other diseases, including multiple sclerosis and idiopathic normal-pressure hydrocephalus. Both patients had extended WMHs in addition to multiple lacunes and microbleeds on brain MR images, which are characteristic of CSVD. If lacunes or microbleeds are found in patients with severe WMHs, genetic tests for hereditary CSVD should be considered.

Age-related demethylation of the TDP-43 autoregulatory region in the human motor cortex.

In amyotrophic lateral sclerosis (ALS), TAR DNA-binding protein 43 (TDP-43), which is encoded by TARDBP, forms aggregates in the motor cortex. This aggregate formation may be triggered by an increase in the TDP-43 level with aging. However, the amount of TDP-43 is autoregulated by alternative splicing of the TARDBP 3'UTR, and how this autoregulation is affected by aging remains to be elucidated. We found that DNA demethylation in the autoregulatory region in the TARDBP 3'UTR reduced alternative splicing and increased TARDBP mRNA expression. Furthermore, in the human motor cortex, we found that this region was demethylated with aging, resulting in increased expression of TARDBP mRNA. The acceleration of DNA demethylation in the motor cortex was associated with the age of ALS onset. In summary, the dysregulation of TDP-43 autoregulation by age-related DNA demethylation in the motor cortex may explain the contribution of aging and motor system selectivity in ALS.

[Molecular Pathogenesis of Amyotrophic Lateral Sclerosis].

The molecular pathogenesis of amyotrophic lateral sclerosis (ALS) has been studied through analysis of the function of the protein produced by the causative genes of familial ALS. The products of these genes are classified as RNA binding proteins, or proteins related to proteolytic systems. However, most case of familial ALS, and sporadic ALS show TAR DNA binding protein-43 (TDP-43) immune-positive cytoplasmic inclusions. Therefore, the molecular mechanism of formation of TDP-43 inclusions and dysfunction caused by TDP-43 inclusions has been studied. As for the mechanism of inclusion formation, non-membrane organelle formation by liquid-liquid phase separation (LLPS) is important. The ubiquitin-proteasome and autophagy systems are important for the degradation of these inclusions. Several genes associated with these systems have been identified as causative genes for ALS. The formation of cytoplasmic inclusions results in the loss of TDP-43 from the nucleus, resulting in abnormalities in RNA metabolism, through the alteration of spliceosomes and Gemini of coiled bodies. Furthermore, in ALS, the regulation of TDP-43 mRNA/protein expression levels has failed. Failure of the autoregulation system facilitates TDP-43 inclusion formation. Development of treatments for ALS based on these elucidated molecular mechanisms is desirable.

Herpes simplex encephalitis presenting as stroke-like symptoms with atypical MRI findings and lacking cerebrospinal fluid pleocytosis.

A 73-year-old woman presented with sudden onset of right hemiparesis and was diagnosed as having cerebral infarction on the basis of diffusion-weighted brain MRI, which demonstrated lesions in the left parietal cortex. On the 3rd day, the patient developed right upper limb myoclonus, aphasia, and disturbance of consciousness with high fever. On the 6th day, she was transferred to our hospital with suspected viral encephalitis, and treatment with acyclovir was started. By the 6th day, the lesions detected by MRI had expanded to the gyrus cinguli, insula and thalamus, but not to the temporal lobe. At that time, the CSF cell count was 8/µl, and this later increased to 17/µl by the 13th day. Although herpes simplex virus DNA was detected in the CSF on the 6th day, there was no evidence of CSF pleocytosis or temporal lobe abnormalities demonstrable by brain MRI throughout the whole follow-up period. This was very atypical case of herpes simplex encephalitis characterized by a stroke-like episode, atypical MRI findings, and absence of cerebrospinal fluid pleocytosis. It is important to be mindful that herpes simplex encephalitis (HSE) can have an atypical presentation, and that sufficient acyclovir treatment should be initiated until HSE can be ruled out.

A case of slowly progressive anti-Yo-associated paraneoplastic cerebellar degeneration successfully treated with antitumor and immunotherapy.

We report a case of slowly progressive anti-Yo-associated paraneoplastic cerebellar degeneration (PCD) with breast cancer in a 54-year-old woman. The symptoms of limb and truncal ataxia, and dysarthria gradually progressed during the course of 1 year, and the modified Rankin scale (mRS) score was 2. A mastectomy with sentinel lymph node resection was performed for the breast cancer. No malignant cells were found on histopathological examination of the lymph node. Combination chemotherapy with adriamycin and cyclophosphamide (AC) prevented neurologic deterioration. However, subsequent treatment with trastuzumab and paclitaxel did not prevent progression of the symptoms (mRS score 3). Brain magnetic resonance imaging showed atrophy of the cerebellar hemispheres without brain stem atrophy. Anti-Yo antibody was detected in the serum, which led to a diagnosis of anti-Yo-associated PCD. We resected an enlarged axillary lymph node, which was found on computed tomography. The histopathological analysis of the lymph node revealed foreign body granuloma, which suggested an association with necrotic malignant tissue. Following additional tegafur-uracil therapy and two courses of intravenous immunoglobulin (IVIg), the cerebellar signs and symptoms gradually improved (mRS score 2). The clinical course shows that PCD can present as a slowly progressive cerebellar symptom. We propose an active treatment for anti-Yo-associated PCD consisting of tumor resection, combined chemotherapy, and IVIg.