When Blood Cell Counts Matter: Hypereosinophilic Syndrome as a Rare Cause of Ischemic Strokes.

Hypereosinophilic syndrome (HES) is a rare condition characterized by elevated eosinophil counts (>1.5 x 109 on two consecutive measurements), which are of myeloid clonal in origin or are driven by excess cytokines. One subtype of HES exhibits the Fip1-like 1-platelet-derived growth factor receptor alpha (FIP1L1-PDGFRA) fusion gene, a gain-of-function mutation resulting in a hyperactive tyrosine kinase. HES, especially the FIP1L1-PDGFRA variant, exhibits an excellent response to chemotherapy with imatinib. In this report, we present a 38-year-old patient with no contributory past medical history who experienced sudden-onset fatigue, ataxia, visual changes, and headaches. He was found to have multiple small acute infarcts in his cerebrum and cerebellum. A stroke work-up, including transthoracic echocardiogram (TTE), transesophageal echocardiogram (TEE), and computed tomography angiography (CTA), did not yield insight into the origin of his infarcts. On CBC, he was consistently hypereosinophilic, and a bone marrow biopsy revealed hypercellularity and the FIP1L1-PDGFRA fusion gene, confirming the diagnosis of HES. The patient was treated first with methylprednisolone and then imatinib with excellent response. It appears that, in our patient, strokes were not of a thromboembolic nature but rather due to hypercoagulability. In this report, we advocate for considering HES and emphasize the importance of revisiting basic laboratory studies such as a CBC if the standard stroke workup fails to elucidate the mechanism behind ischemic strokes with an embolic pattern.

When the Music Comes From the Brain: A Rare Case of Auditory Seizures Secondary to a Right Temporal Lobe Arteriovenous Malformation.

Focal seizures with subjective auditory phenomena, known as auditory seizures, are uncommon and can include simple to complex auditory hallucinations. We present a case of a 59-year-old man who presented with motor and non-motor seizures. He had a four-month history of hearing things resembling continuous metallic sounds, pennies dropping into a bank, persistent music after radio cessation, and the sound of a passing train. Brain MRI showed multiple serpiginous flow voids in the right temporal lobes, consistent with an arteriovenous malformation that was confirmed eventually with a diagnostic brain angiogram. The etiology of the seizures was related to a structural lesion in the setting of a right temporal arteriovenous malformation (AVM). Treatment with 2000mg of levetiracetam twice daily and 300mg of oxcarbazepine twice daily improved symptoms, and subsequent stereotactic radiosurgery ablation successfully treated the AVM. Post-treatment MRI showed reduced visibility of parasitized vessels, with controlled generalized seizures but partial control of auditory seizures.

Deep Brain Stimulation for Medication Refractory Tremor in Leber Optic Neuropathy Plus Syndrome.

Leber hereditary optic neuropathy (LHON) is a mitochondrial disorder that presents with acute to subacute onset of unilateral progressive optic neuropathy, with sequential involvement of the fellow eye months to years later. The condition may be accompanied by neurological symptoms, including tremors, dystonia, seizures, or psychosis, in which case, it is termed LHON-plus. Here, we present the case of a 53-year-old man who was initially diagnosed with essential tremor but was later found to have LHON-plus after the onset of bilateral visual loss and a genetic panel. His essential tremor was refractory to standard pharmacological therapies, including propranolol, primidone, and topiramate. As a result, he elected to undergo bilateral deep brain stimulation (DBS) of the bilateral ventral intermediate nucleus of the thalamus with a dramatic improvement in symptoms. To our knowledge, this is the first case of essential tremor presenting in the context of LHON-plus to be treated successfully with DBS. While DBS has been applied in LHON-plus presenting with dystonia with limited success, our outcome suggests that there is promise in this approach and that more research is needed to evaluate it.