Bilateral thalamic lesions: A pictorial review

Neuroimaging of complications arising after CD19 chimeric antigen receptor T-cell therapy: A review

Chimeric antigen receptor (CAR) T cells targeting the CD19 (cluster of differentiation 19) cell surface glycoprotein have emerged as a highly effective immunologic therapy in patients with relapsed or refractory B-cell malignancies. The engagement of CAR T cells with CD19 on the surface of neoplastic B cells causes a systemic cytokine release, which can compromise the blood-brain barrier and cause an immune effector cell-associated neurotoxicity syndrome (ICANS). In a small proportion of ICANS patients who demonstrate neuroimaging abnormalities, certain distinct patterns have been recognized, including signal changes in the thalami, external capsule, and brainstem, the subcortical and/or periventricular white matter, the splenium of the corpus callosum, and the cerebellum. On careful review of the underlying pathophysiology of ICANS, we noticed that these changes closely mirror the underlying blood-brain barrier disruption and neuroinflammatory and excitotoxic effects of the offending cytokines released during ICANS. Furthermore, other uncommon complications of CD19 CAR T-cell therapy such as posterior reversible encephalopathy syndrome, ocular complications, and opportunistic fungal infections can be catastrophic if not diagnosed in a timely manner, with neuroimaging playing a significant role in management. In this narrative review, we will summarize the current literature on the spectrum of neuroimaging findings in ICANS, list appropriate differential diagnoses, and explore the imaging features of other uncommon central nervous system complications of CD19 CAR T-cell therapy using illustrative cases from two tertiary care institutions.

Dural Arteriovenous Fistula Presenting as a Rapidly Progressive Thalamic Dementia: A Case Report

Rapidly progressive dementia is an uncommon neurological presentation and usually needs extensive workup, especially for reversible causes. Dural arteriovenous fistula (DAVF) has been rarely reported as a cause of thalamic dementia, in which bilateral thalamic venous congestion and edema cause dementia that usually progresses rapidly. We present a case of a 45 years-old male who presented with rapidly progressive severe attention and memory impairment over one week. Initial work-up showed bilateral thalamic recent venous infarctions and edema. Extensive work-up revealed an intracranial DAVF with internal deep venous thrombosis. Management with endovascular treatment of DAVF followed by anticoagulation for venous thrombosis leads to improvement of the patient’s clinical condition, particularly memory and attention. In conclusion, DAFV could present with thalamic rapidly progressive dementia due to bithalamic infarctions and edema. Early diagnosis and treatment will reverse the cause and improve the patient's general and cognitive conditions.

Evaluation of neuroimaging findings in thalamic lesions: what can we think?

The diseases that affect the thalamus are heterogeneous in their etiologies, including infectious, inflammatory, vascular, toxic-metabolic, and neoplastic causes. It is often difficult to make the clinical differentiation between different entities. Within this context, computed tomography and magnetic resonance imaging have come to be of fundamental importance for defining the etiology and planning the treatment. In this pictorial essay, we will illustrate the main causes of diseases affecting the thalamus, discussing the possible differential diagnoses, as well as the most relevant imaging aspects.

Osmotic demyelination syndrome diagnosed radiologically during Wilson's disease investigation

Wilson's disease (WD), also known as hepatolenticular degeneration, is a rare autosomal recessive disorder that results from abnormal ceruloplasmin metabolism, with copper deposition affecting multiple systems. Osmotic demyelination syndrome (ODS) refers to acute demyelination seen in the setting of osmotic changes, typically with the rapid correction of electrolyte disturbance. We present a 29-year-old male patient diagnosed with WD 1 year after the onset of extrapyramidal symptoms. Magnetic resonance imaging performed during hospitalization showed two patterns of pons involvement, which allowed the diagnosis of ODS in addition to WD. Classic imaging findings were observed and illustrate perfectly these two conditions.

Bilateral thalamic changes in anti-NMDAR encephalitis presenting with hemichorea and dystonia and acute transient psychotic disorder

Anti-N-methyl-d-aspartate receptor (anti-NMDAR) encephalitis is one of the most common causes of autoimmune encephalitis. Both movement disorders and neuropsychiatric manifestations are considered core features of anti-NMDAR encephalitis. Strong clinical suspicion, along with NMDAR antibody positivity in paired sample of serum and cerebrospinal fluid, with supportive MRI changes clinch diagnosis in majority. We herein report a case of a middle-aged woman with subacute behavioral abnormalities, which were so severe that forced her to attempt suicide. Hemichorea and dystonia, which appeared later in course, are not previously reported movement disorders in combination in anti-NMDAR encephalitis. Further, magnetic resonance imaging showed bilateral thalamic hyperintensities with diffusion restriction, which are in turn not described in this entity. After amalgamation of history, especially the presence of neuropsychiatric symptoms, clinical features, physical examination, and investigations, the diagnosis of anti-NMDAR encephalitis could be established. Our case not only highlights that the combination of hemichorea and dystonia can be features of anti-NMDAR encephalitis, but adds novelty by bilateral symmetric thalamic changes.

[A case suspected of dystonia with marked cerebellar atrophy with torsion dystonia of the neck and cerebellar ataxia that developed during pharmacologic schizophrenia treatment]

A 46 year-old man with schizophrenia had taken several anti-psychotic drugs since 25 years of age. From ~35 years of age, he noticed occasional neck torsion to the left, and later an ataxic gait; both symptoms gradually worsened. On admission, the patient was taking olanzapine (5 mg/day) and biperiden hydrochloride (1 mg/day) because his schizophrenia was well controlled. His parents were not consanguineous, and there was no family history of neuropsychiatric diseases. On neurological examination, he showed mild cognitive impairment, saccadic eye pursuit with horizontal gaze nystagmus, mild dysarthria, dystonic posture and movement of the neck, incoordination of both hands, and an ataxic gait. Deep tendon reflexes were normal except for the patellar tendon reflex, which was exaggerated bilaterally. Pathological reflexes were negative and there was no sign of rigidity, sensory disturbance or autonomic dysfunction. Ophthalmological examinations detected thinning of the outer macula lutea in both eyes, indicative of macular dystrophy. After admission, all anti-psychotic drugs were ceased, but his dystonia was unchanged. Levodopa and trihexyphenidyl hydrochloride were not effective. General blood, urine and cerebrospinal fluid examinations showed no abnormalities. Brain MRI showed cerebellar atrophy and bilateral symmetrical thalamic lesions without brainstem atrophy or abnormal signals in the basal ganglia. I¹²³-IMP SPECT also revealed a decreased blood flow in the cerebellum. Genetic screening, including whole exome sequencing conducted by the Initiative on Rare and Undiagnosed Disease identified no possible disease-causing variants. The patient's dystonia worsened and choreic movements manifested on his right hand and foot. We suspected dystonia with marked cerebellar atrophy (DYTCA), but could not exclude drug-induced dystonia. Macular dystrophy and bilateral thalamic lesions on brain MRI have not been previously described in DYTCA. Whether these features might be primarily associated with dystonia or cerebellar ataxia now remains to be determined.

Bilateral thalamic lesions in a patient with probable acute disseminating encephalomyelitis: a case report

BACKGROUND

Bilateral thalamic lesions are rare. Here, we describe a case of probable acute disseminating encephalomyelitis (ADEM) with symmetrical bilateral thalamic lesions.

CASE PRESENTATION

An 85-year-old man presented with weakness of the lower limbs and urinary retention for 1 day, soon followed by coma. He had an H1N1 influenza vaccination 3 months ago. A lumbar puncture showed positive oligoclonal bands and negative results for anti-AQP4 antibodies. A head MRI demonstrated focal symmetrical bilateral thalamic lesions. An MRI of the thoracic spinal cord showed longitudinally extensive lesions in the spinal cord. He was diagnosed with probable ADEM. Despite being treated with IVIG, the patient remained unconscious and died a month later from pneumonia.

CONCLUSIONS

In cases with bilateral thalamic lesions, the possibility of ADEM should be considered. The characteristics of the thalamic lesions and imaging findings in other parts of the brain or spinal cord should be taken into account in association with the clinical and laboratory information in making a correct diagnosis.