Bilateral Anterior Cerebral Artery Strokes

Some Embolic strokes of undetermined origin (ESUS) are extremely rare. That is the case of a patient with multiple vascular risk factors who presented with persistent inability to get up after a fall at home. Physical examination revealed only mild left-sided claudication. Magnetic resonance imaging showed multiple paramedian emboli in both cerebral hemispheres, with normal cardiac tests (echocardiogram; Holter ECG).

Finally, a CT angiogram revealed a high grade stenosis of an azygos anterior cerebral artery. The patient had a prothrombotic state due to poorly controlled vascular risk factors and very low vitamin B12 levels.

Image source: 

https://www.neuroradiologycases.com/2012/04/azygus-aca.html

The importance of gait and steadiness assessment

 

In patients presenting with acute or subacute neurological deterioration, the physical examination may be nonspecific, being essential, whenever it is possible, to assess their steadiness and gait, independently or with assistance. 

Gait and steadiness are a highly complex functions requiring the precise synchronization of numerous neural pathways. Therefore, when the brain exhibits diffuse impairment, as in delirium, or when one of these pathways is damaged, as in a mild stroke, both will be affected and, sometimes, will be the only clue in the entire clinical examination to guide the investigation.

Source: “Figure - PMC.” Nih.gov, 2016, pmc.ncbi.nlm.nih.gov/articles/PMC5318488/figure/Fig1/. Accessed 8 Dec. 2025.

Rheumatoid meningitis

There must be some epitope in the connective tissue of the falx cerebri to justify the characteristic radiological pattern seen in some forms of rheumatoid meningitis. There is observed contrast uptake in the meninges with surrounding parasagittal vasogenic edema and restricted diffusion in DWI MRI, likely in relation to local inflammatory changes with poorly soluble organized tissue due to rheumatoid nodules.

Figures from:

https://n.neurology.org/content/66/6/948/tab-figures-data

https://brieflands.com/articles/ans-20570.html

Meningitis due to CSF fistula of the skull base

Some individuals may develop acute meningitis secondary to skull defect between the anterior cranial fossa and the nasal cavity. The presence of CSF rhinorrhea in the previous days is the clue for the diagnosis. This symptom orient to order specific neuroimagen tests, as the high-resolution computed tomography scan (HRCT), with the aim to locate the skull defect. Routine biochemical tests are performed to establish the differential diagnosis between CSF and nasal discharge. Glucose is higher in CSF and proteins are higher in mucus. The presence of Beta 2-transferrin also is orientative of CSF. The ethiological microorganisms are those common of superior respiratory tract, which may be treated with conventional antibiotics schemes. If the CSF leak doesn't close spontaneuosly in 7-10 days, it’s necessary a neurosurgical/ENT consult to repair the skull defect for avoiding a recurrence. 

Gretchen et al propose a practical algortihm to approach these situations: 

Sources and images: 

• Shelesko EV, Kravchuk AD, Kapitanov DN, Chernikova NA, Zinkevich DN. Sovremennyĭ podkhod k diagnostike nazal'noĭ likvorei [A modern approach to the diagnosis of nasal liquorrhea]. Zh Vopr Neirokhir Im N N Burdenko. 2018;82(3):103-111. Russian. doi: 10.17116/neiro2018823103. PMID: 29927432.
• Gretchen MO, Jeremiah A, Schlosser RJ, Harvey RJ, Orlandi RR. Diagnosis of cerebrospinal fluid rhinorrhea: an evidence-based review with recommendations. International Forum of Allergy & Rhinology. 2016;6:1.
• https://pgblazer.com/cerebrospinal-fluid-csf-vs-nasal-discharge-differences/

Vertigo

Vertigo 

Thalamic hyperintensity in seizure stroke mimic.

Acute aphasia is one of the most common forms of presentation of stroke mimics. Many times those patients are having seizures. When there’s a suspicion of a stroke mimic, MRI is better than multiparametric CT on the differential diagnosis. In some patients, we can see a thalamic hyperintensity ipsilateral to the hemisphere with ictal activity.

Franklin Nwokea, Yuebing Lia. Focal Thalamic and Cortical Magnetic Resonance Changes Associated With Partial Status Epilepticus

Hipertrofia olivar degenerativa secundaria a ictus isquémico

La degeneración olivar hipetrófica es una variedad peculiar de degeneración "transináptica" en la que en vez de atrofia, se produce una vacuolización citoplasmática que genera hinchazón neuronal. Acontece tras lesiones de la vías nerviosas que transcurren entre el núcleo dentado cerebeloso de un lado y el núcleo rojo mesencefálico y el núcleo olivar inferior bulbar contralaterales. Es el circuito conocido como triángulo de Guillain-Mollaret.

RM (secuencia de difusión): Ictus isqúemico agudo protuberancial que involucra al tracto tegmental central derecho.

RM de control al año (secuencia T2): se observa el infarto crónico protuberancial derecho (flecha continua) y la degeneración olivar hipertrófica ipsilateral (flecha discontinua). 

En la figura de abajo (secuencia flair) se aprecia también en un corte axial la hipetrofia olivar.