Izumi Sugimoto

Isolated thalamic agraphia with impaired grapheme formation and micrographia.

Two patients with isolated thalamic agraphia are described. Both showed kanji (Japanese morphograms) agraphia due to impaired character recall, grapheme deformity and micrographia (progressive reduction in character size during writing) after a lesion that involved the ventral lateral and ventroposterolateral nuclei. Single photon emission computed tomography with a 99mTc-ethylcysteinate dimer revealed hypoperfusion in the left precentral gyrus (Brodmann Area 6) and anterior supramarginal gyrus in both. Six months later, the extent of blood flow reduction decreased in the supramarginal gyrus in both patients and the precentral gyrus in patient 1. By this time, the writing impairment improved to nearly the normal range. Our study suggests that kanji agraphia (corresponding to lexical agraphia in Western countries) with poor grapheme formation and micrographia arises from a lesion in the ventral lateral and ventroposterolateral nuclei in the left thalamus. The accompaniment of poor grapheme formation and micrographia may reflect disruption of the cortico-subcortical motor circuit involving the putamen, thalamus, premotor cortex and sensorimotor cortex. It is also suggested that multiple cortical sites can be a target for secondary dysfunction that yields agraphia in a thalamic lesion, and that the recovery of reduced cortical blood flow does not always proceed in parallel with that of agraphia.

Progressive apraxic agraphia with micrographia presenting as corticobasal syndrome showing extensive Pittsburgh compound B uptake.

A 65-year-old woman developed progressive apraxic agraphia, characterized by poorly formed graphemes, a kanji (Japanese morphograms) recall impairment, relatively preserved oral spelling of kanji characters, and incorrect stroke sequences on writing accompanied by micrographia over a 3-year period. She also showed minor degrees of rigidity, limb-kinetic apraxia, and ideomotor apraxia of the left hand. Although asymmetric rigidity and limb-kinetic apraxia strongly suggested corticobasal degeneration, 11C-Pittsburgh compound B positron emission tomography (PiB-PET) showed the predominantly right-sided accumulation of amyloid β in the cortices and striatum. 18F-fluoro-deoxy-glucose PET and single photon emission computed tomography with a 99mTc-ethylcysteinate dimer (ECD-SPECT) also revealed predominantly right-sided hypometabolism and hypoperfusion in the primary sensorimotor cortex, posterior cingulate gyrus, temporoparietal cortices, frontal cortices, thalamus, and basal ganglia, a pattern characteristic of both corticobasal degeneration and Alzheimer’s disease. The findings suggest that progressive apraxic agraphia with micrographia presenting as corticobasal syndrome can show an Alzheimer’s disease pathology. It is also suggested that ideomotor apraxia of the left hand can occur without a callosal lesion, and is caused by hypometabolism or hypoperfusion in the right frontal and parietal cortices, as revealed by PET and SPECT.

Anti-Glutamate ε2 Receptor Antibody-Positive and Anti-N-Methyl-D-Aspartate Receptor Antibody-Negative Lobar Encephalitis Presenting as Global Aphasia and Swallowing Apraxia

Background: Little is known about the difference between anti-N-methyl-D-aspartate receptor (NMDAR) antibody-positive encephalitis and anti-glutamate receptor (GluR) antibody-positive encephalitis. Objectives: To characterize anti-GluR antibody-positive encephalitis. Methods: We report a 33-year-old man with nonparaneoplastic anti-GluR ε2, ζ1 and δ2 antibody-positive and anti-NMDAR antibody-negative encephalitis, using neuropsychological tests and imaging studies including magnetic resonance imaging and single photon emission computed tomography (SPECT) with a 99mTc-ethylcysteinate dimer. Results: The patient exhibited global aphasia and swallowing apraxia (inability to transfer food to the pharyngeal cavity without sialorrhea). He was treated with 3 courses of corticosteroid pulse therapy and had recovered markedly 3 weeks after onset. Magnetic resonance diffusion-weighted images revealed hyperintensity in the bilateral frontal and left parietal cortices. Seven months later, a small area of hyperintensity in the left supramarginal gyrus remained. SPECT revealed hypoperfusion in extensive regions of the bilateral frontal lobes and left supramarginal gyrus. Thirteen months later, blood flow reduction was restricted to diffuse areas in the frontal lobes. Conclusions: Frontal lobar encephalitis without medial temporal involvement, marked cognitive impairment with a relatively preserved level of consciousness, and a favorable response to corticosteroid therapy, with nearly reversible cortical damage, may characterize anti-GluR antibody-positive encephalitis.

Ventral simultanagnosia and prosopagnosia for unfamiliar faces due to a right posterior superior temporal sulcus and angular gyrus lesion

We report a patient with ventral simultanagnosia, prosopagnosia for “unfamiliar faces” (dorsal prosopagnosia), spatial agraphia, and constructional disorder, particularly on the left spatial side, due to a lesion in the right posterior superior and middle temporal gyri and angular gyrus. The patient showed impairment of fundamental visual and visuospatial recognition, such as in object size, configuration, and horizontal point location, which probably underlay the mechanism of simultanagnosia and prosopagnosia. This case also suggests that the coexistence of simultanagnosia and prosopagnosia results from a right hemispheric insult, and damage to the temporoparietal area interrupts the incorporation of spatial information into object recognition. This disconnection of information flow, together with impaired object recognition per se, may impair the parallel processing of multiple objects, leading to object-by-object or part-by-part recognition.

Frontal Phonological Agraphia and Acalculia with Impaired Verbal Short-Term Memory due to Left Inferior Precentral Gyrus Lesion

We report a patient with phonological agraphia (selective impairment of kana [Japanese phonetic writing] nonwords) and acalculia (mental arithmetic difficulties) with impaired verbal short-term memory after a cerebral hemorrhage in the opercular part of the left precentral gyrus (Brodmann area 6) and the adjacent postcentral gyrus. The patient showed phonemic paragraphia in five-character kana nonword writing, minimal acalculia, and reduced digit and letter span. Mental arithmetic normalized after 8 months and agraphia recovered to the normal range at 1 year after onset, in parallel with an improvement of the auditory letter span score from 4 to 6 over a period of 14 months and in the digit span score from 6 to 7 over 24 months. These results suggest a close relationship between the recovery of agraphia and acalculia and the improvement of verbal short-term memory. The present case also suggests that the opercular part of the precentral gyrus constitutes the phonological route in writing that conveys phonological information of syllable sequences, and its damage causes phonological agraphia and acalculia with reduced verbal short-term memory.

Unilateral hypoglossal nerve palsy with asymmetric facial and limb paresis in axonal Guillain–Barré syndrome

We report a 45‐year‐old man with motor axonal Guillain–Barré syndrome who developed left facial nerve palsy, right hypoglossal nerve palsy, and predominantly left‐sided upper limb paresis and left lower limb paresis. Blood examination identified immunoglobulin G antibodies against gangliosides GD1a, GD1b and GQ1b, and GD1b/GD1a and GD1b/GT1b complexes. He was treated with intravenous immunoglobulin (400 mg/kg/day for 5 days) twice, and tongue deviation and facial palsy resolved in 3 months. Unilateral or asymmetric involvement of the cranial and limb nerves represent a variant form of axonal Guillain–Barré syndrome.

Repetitive Discharge in a Case of Isaacs Syndrome with Burning Sensation

A 66-year-old man consulted a physician with 1-and-ahalf-year history of a burning sensation in all of his extremities without muscle weakness or reduced sensation. Screening tests for neuropathy revealed slightly elevated hemoglobin-A1c but otherwise normal findings. A nerve conduction study (NCS) showed a normal amplitude and velocity, and the physician did not consult a neurologist. Four months later, the patient presented to our neurology clinic with worsening symptoms. Taking his history revealed frequent muscle cramps, and myokymia was noted in both calves, suggesting Isaacs syndrome. NCS showed abnormal repetitive discharges after compound muscle action potential, which were also found in the first NCS (Picture A). Serum anti-voltage-gated potassium channel (VGKC) antibodies were positive. Antiepileptic drugs and immunoadsorption plasmapheresis plus steroid pulse therapy were started, followed by oral prednisolone (30 mg/day), resulting in symptom improvement. A follow-up NCS after symptom improvement showed the near disappearance of abnormal repetitive discharges (Picture B). Isaacs syndrome is an autoimmune neurological disease typically presenting with frequent muscle cramps (1). However, a burning sensation can also be the initial complaint, as in our patient (2). NCS results, including a visual assessment of the wave, should be cautiously interpreted.

Asymmetric oculomotor apraxia, optic ataxia, and simultanagnosia with right hemispatial neglect from a predominantly left-sided lesion of the parieto-occipital area

ABSTRACT Introduction: Bálint’s syndrome involves bilateral damage to the parieto-occipital area. The extent of the effect of unilateral damage on the Bálint’s triad (oculomotor apraxia, optic ataxia, and simultanagnosia) remains unknown. Methods: We examined a 63-year-old, right-handed woman who developed right hemianopia, oculomotor apraxia, optic ataxia, simultanagnosia, and hemispatial neglect (HSN) for the right after a cerebral infarction, with detailed neuropsychological tests, magnetic resonance imaging, and single photon emission computed tomography (SPECT). Results: Neuropsychological examination showed that oculomotor apraxia, optic ataxia, and simultanagnosia were more pronounced in the right hemi-space, probably due to the limited eye movement in the right visual field, whereas HSN was restricted to the right hemi-space. Diffusion-weighted MR images revealed hyperintensity in the left parieto-temporo-occipital region, and several spotty areas of the bilateral frontal and parietal subcortical regions. SPECT revealed hypoperfusion in the left parieto-occipital region and frontal operculum and small areas of the right superior parietal lobule. Conclusions: The case suggests that asymmetric (more pronounced in the right hemi-space) oculomotor apraxia, optic ataxia, and simultanagnosia occur in an extensive lesion of the left parieto-occipital cortices. Although HSN is not a prerequisite for simultanagnosia, the coexistence of HSN aggravates simultanagnosia in the hemi-space opposite the lesion.

High PR3-ANCA positivity in a patient with chronic inflammatory demyelinating polyneuropathy

Proteinase 3 anti-neutrophil cytoplasmic antibody (PR3-ANCA) is reported to be highly specific to vasculitis compared to myeloperoxidase (MPO)-ANCA. We report a case of a 19-year-old woman with chronic inflammatory demyelinating polyneuropathy (CIDP) with high PR3-ANCA positivity. The patient responded well to intravenous immunoglobulin plus oral steroid, and showed no signs of systemic vasculitis during the subsequent 10 months of follow-up. Our present case suggests that CIDP may accompany high PR3-ANCA levels, which should be differentiated from axonal neuropathy due to vasculitis.

Subacute lobar encephalitis presenting as cerebellar ataxia and generalized cognitive impairment with positive anti‐glutamate receptor antibodies

We report a patient with anti‐glutamate receptor (GluN2B, GluN1 and GluD2) antibody‐positive and anti‐N‐methyl‐d‐aspartate receptor antibody‐negative encephalitis presenting as cerebellar ataxia and generalized cognitive impairment. Intravenous corticosteroid pulse therapy markedly resolved his symptoms 6 weeks after onset. Marked impairment of the cortical function with a relatively preserved level of consciousness, and a favorable response to corticosteroid therapy might occur in immune‐mediated lobar encephalitis associated with anti‐glutamate receptor antibodies.