Diagnostic value of contrast-enhanced 3D FLAIR sequence in acute optic neuritis.

PURPOSE: Contrast-enhanced fluid-attenuated inversion recovery (FLAIR) sequence of the brain has the potential for detecting optic nerve abnormality. This study aimed to compare the diagnostic value of whole-brain contrast-enhanced three-dimensional FLAIR with fat suppression (CE 3D FLAIR FS) sequence in detecting acute optic neuritis to dedicated orbit MRI and clinical diagnosis. MATERIALS AND METHODS: Twenty-two patients with acute optic neuritis who underwent whole-brain CE-3D-FLAIR FS and dedicated orbit MRI were retrospectively included. The hypersignal FLAIR of the optic nerve on whole-brain CE-3D-FLAIR FS, enhancement, and hypersignal T2W on orbit images were assessed. The optic nerve to frontal white matter signal intensity ratio on CE-FLAIR FS was calculated as maximum signal intensity ratio (SIR) and mean SIR. RESULTS: Twenty-six hypersignals of optic nerves were found on CE-FLAIR FS from 30 pathologic nerves. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of CE FLAIR FS brain and dedicated orbital images for diagnosing acute optic neuritis were 77%, 93%, 96%, 65%, and 82% and 83%, 93%, 96%, 72%, and 86%, respectively. Optic nerve to frontal white matter SIR of the affected optic nerves was higher than that of normal optic nerves. Using a cutoff maximum SIR of 1.24 and cutoff mean SIR of 1.16, the sensitivity, specificity, PPV, NPV, and accuracy were 93%, 86%, 93%, 80%, and 89% and 93%, 86%, 93%, 86%, and 91%, respectively. CONCLUSION: The hypersignal of the optic nerve on whole-brain CE 3D FLAIR FS sequence has qualitative and quantitative diagnostic potential in patients with acute optic neuritis.

Automated CT registration tool improves sensitivity to change in ventricular volume in patients with shunts and drains.

OBJECTIVE: CT is the mainstay imaging modality for assessing change in ventricular volume in patients with ventricular shunts or external ventricular drains (EVDs). We evaluated the performance of a novel fully automated CT registration and subtraction method to improve reader accuracy and confidence compared with standard CT. METHODS: In a retrospective evaluation of 49 ventricular shunt or EVD patients who underwent sequential head CT scans with an automated CT registration tool (CT CoPilot), three readers were assessed on their ability to discern change in ventricular volume between scans using standard axial CT images versus reformats and subtraction images generated by the registration tool. The inter-rater reliability among the readers was calculated using an intraclass correlation coefficient (ICC). Bland-Altman tests were performed to determine reader performance compared to semi-quantitative assessment using the bifrontal horn and third ventricular width. McNemar's test was used to determine whether the use of the registration tool increased the reader's level of confidence. RESULTS: Inter-rater reliability was higher when using the output of the registration tool (single measure ICC of 0.909 with versus 0.755 without the tool). Agreement between the readers' assessment of ventricular volume change and the semi-quantitative assessment improved with the registration tool (limits of agreement 4.1 vs 4.3). Furthermore, the tool improved reader confidence in determining increased or decreased ventricular volume (p < 0.001). CONCLUSION: Automated CT registration and subtraction improves the reader's ability to detect change in ventricular volume between sequential scans in patients with ventricular shunts or EVDs. ADVANCES IN KNOWLEDGE: Our automated CT registration and subtraction method may serve as a promising generalizable tool for accurate assessment of change in ventricular volume, which can significantly affect clinical management.

Isolated Horner syndrome as a rare initial presentation of nasopharyngeal carcinoma: a case report.

BACKGROUND: Horner syndrome refers to a set of clinical presentations resulting from disruption of sympathetic innervation to the eye and adnexa. Classically, the clinical triad consists of ipsilateral blepharoptosis, pupillary miosis, and facial anhidrosis. Ocular sympathetic denervation may signify life-threatening causes. Timely investigation and accurate diagnosis are essential in patients with oculosympathetic denervation. CASE PRESENTATION: A 33-year-old Asian man with a heavy smoking habit presented with a 3-week history of left ptosis and no other complaints. His visual acuity was 20/20 bilaterally. An ophthalmic examination was significant for mild ptosis of his left eyelid and anisocoria (smaller left pupil), which was greater in the dark. Both pupils reacted to light briskly without an afferent pupillary defect. Anhidrosis was found on the medial side of the left forehead. A 10% cocaine test was positive. At his first visit, neurologic examination was unremarkable. Comprehensive radiological investigations were scheduled for a left-sided isolated Horner syndrome. Two weeks after his first visit, he experienced a left-sided headache along with ipsilateral Horner syndrome. Neurologic examination revealed hypoesthesia in the left cranial nerve V1-3 territories. Emergent computed tomography angiography was suspected for petrous part of the left internal carotid artery (ICA) dissection. Magnetic resonance imaging demonstrated an enhancing infiltrative lesion with its epicenter at the left sphenoid bone. The lesion encased the left ICA and invaded the left Meckel cave. Rhinoscopy with incisional biopsy revealed squamous cell nasopharyngeal carcinoma. CONCLUSION: This case involved an unusual initial presentation of nasopharyngeal carcinoma: isolated Horner syndrome with clinical progression to adjacent structures. Infiltration involving the Meckel cave and ICA at the foramen lacerum can present as postganglionic Horner syndrome associated with trigeminal pain and hypoesthesia. These clinical findings may mimic carotid artery dissection on computed tomography angiography. Detailed magnetic resonance imaging with careful attention to the skull base should be performed.

Isolated optic neuritis with a concurrent abnormal trigeminal nucleus on imaging: case report of a rare complication of herpes zoster ophthalmicus.

BACKGROUND: Herpes zoster ophthalmicus (HZO) is an inflammation related to reactivation of the latent varicella zoster virus (VZV), involving the ophthalmic branch of the trigeminal nerve. Optic neuritis (ON), a rare ocular complication following HZO, has been reported in 1.9% of HZO-affected eyes. Most previous cases occurred simultaneously with other ocular complications, especially orbital apex syndrome. Moreover, detailed magnetic resonance imaging (MRI) with diffusion weighted imaging of the optic nerve and trigeminal nucleus in HZO-related ON has been rarely reported. We report a case of postherpetic isolated ON with a concurrent abnormal trigeminal nucleus on imaging. CASE PRESENTATION: A healthy 58-year-old female presented with sudden painful visual loss in her right eye for 2 days. Four weeks before the presentation, her right eye was diagnosed with HZO, and she received intravenous acyclovir for 10 days. Ophthalmic examination revealed a visual acuity of light perception and 20/20 in the right and left eyes, respectively. A relative afferent pupillary defect was present in the right eye. Neurological examination was significant for hypoesthesia in the area of the HZO. A clinical diagnosis of HZO-related right retrobulbar ON was made, and other causes of atypical ON were excluded. MRI showed enhancement and restricted diffusion of the right-sided optic nerve with linear hyperintense T2 of the right-sided spinal trigeminal nucleus and tract (STNT) along the brainstem. She received 14 days of intravenous acyclovir and 5 days of methylprednisolone. Both were switched to an oral route for 2 months. After the completion of treatment, the visual acuity was counting fingers and 20/20 in the right eye and left eye, respectively. Stable brainstem STNT abnormalities and resolution of ON were found radiologically. CONCLUSIONS: Isolated ON is a rare ocular complication following HZO. An abnormal high signal of STNT on a T2 weighted image may be present, which may be a clue for VZV-associated complications, such as HZO-related ON, especially in cases lacking an obvious history of HZO or other concomitant ocular complications. Prompt treatment with both acyclovir and corticosteroids should be started. Restricted diffusion of the optic nerve may be a predictor for poor visual recovery.

Atypical central retinal artery occlusion as the first presentation of POEMS syndrome: a case report.

BACKGROUND: POEMS syndrome is a plasma cell disorder, which clinically manifests from paraneoplastic syndrome: polyneuropathy, organomegaly, endocrinopathy, monoclonal plasma cell disorder, and skin changes. The most common ocular manifestation is optic disc swelling, whereas other ocular manifestations; cystoid macular edema, serous macular detachment, venous sinus thrombosis, infiltrative orbitopathy, uveitis, neovascularization of the disc, peripapillary choroidal neovascularization and optic disc drusen, had also been reported. CASE PRESENTATION: A 52-year-old Thai man presented with 5-day sudden painless visual loss in the left eye. Ocular examination revealed visual acuity of 20/20 and no light perception in the right and left eye, respectively. Right fundoscopic examination was significant for hyperemic generalized optic disc swelling. Left fundoscopic examination revealed opaque and edematous entire retina giving the appearance of central retinal artery occlusion (CRAO) along with pallid "chalky white" optic disc swelling. Fluorescein angiography showed profound leakage of bilateral optic nerve heads and arteriolar filling defect in macular area along with leakage of small retinal arterioles in the left eye. Indocyanine green angiography demonstrated choroidal filling defect in the left eye only. Neuroimaging showed enhancement and luminal narrowing of left internal carotid artery, early subacute watershed infarctions in the left cerebral hemisphere and pachymeningeal enhancement. Cerebrospinal fluid analysis revealed high protein level with normal opening pressure. Intravenous methylprednisolone was initially started without any benefit. After extensive investigations, diagnosis of "POEMS syndrome" was made based on polyneuropathy, elevated lambda light chain level, elevated plasma vascular endothelial growth factor (VEGF), hepatomegaly, spinal sclerotic bone lesions, and thrombocytosis. Furthermore, sural nerve biopsy demonstrated neuropathy and positive VEGF staining. He was treated with eight cycles of bortezomib, cyclophosphamide and dexamethasone (BorCyDex). Polyneuropathy and thrombocytosis had remarkably improved after 2nd cycle, whereas, visual impairment had shown no recovery. Hepatomegaly was significantly reduced after the completion of BorCyDex. Our case eventually received autologous hematopoietic stem cell transplantation with high dose melphalan. CONCLUSIONS: To our knowledge, we illustrated the first patient given CRAO as the first presentation and ocular finding ever reported in POEMS syndrome. Both cerebral and ocular infarctions were presumably the result of VEGF-induced cranial vasculopathy as evidenced by neuroimaging.

Occipital lobe infarction: a rare presentation of bilateral giant cavernous carotid aneurysms: a case report.

BACKGROUND: Cavernous carotid aneurysm (CCA) represents 2-9% of all intracranial aneurysms and 15% of internal carotid artery (ICA) aneurysms; additionally, giant aneurysms are those aneurysms that are > 25 mm in size. Bilateral CCAs account for 11-29% of patients and are commonly associated with structural weaknesses in the ICA wall, secondary to systemic hypertension. CCAs are considered benign lesions, given the low risk for developing major neurologic morbidities (i.e., subarachnoid hemorrhage, cerebral infarction, or carotid cavernous fistula). Moreover, concurrent presentation with posterior circulation cerebral infarction is even rarer, given different circulation territory from CCA. Here, we report on a patient with bilateral giant CCAs who presented with both typical and atypical symptoms. CASE PRESENTATION: An 88-year-old hypertensive woman presented with acute vertical oblique binocular diplopia, followed by complete ptosis of the right eye. Ophthalmic examination showed dysfunction of the right third, fourth, and sixth cranial nerves. Further examination revealed hypesthesia of the areas supplied by the ophthalmic (V1) and maxillary (V2) branches of the right trigeminal nerve. Bilateral giant cavernous carotid aneurysms, with a concurrent subacute right occipital lobe infarction, were discovered on brain imaging and angiogram. Additionally, a prominent right posterior communicating artery (PCOM) was revealed. Seven months later, clinical improvement with stable radiographic findings was documented without any intervention. CONCLUSIONS: Dysfunction of the third, fourth, and sixth cranial nerves, and the ophthalmic (V1) and maxillary (V2) branches of the trigeminal nerves, should necessitate brain imaging, with special attention given to the cavernous sinus. Despite unilateral symptomatic presentation, bilateral lesions cannot be excluded solely on the basis of clinical findings. CCA should be included in the differential diagnosis of cavernous sinus lesions. Although rare, ipsilateral posterior circulation cerebral infarction (i.e., occipital lobe infarction) can occur in CCA patients, presumably as a result of distal embolization through an ipsilateral, prominent PCOM. Spontaneous clinical improvement with stable radiographic support may occur.

Atypical oculopalatal tremor as the presentation of vertebral artery dolichoectasia.

Vertebrobasilar dolichoectasia (VBD) is a rare dilative arteriopathy defined as elongation or widening of the intracranial vertebral and/or basilar arteries. The prevalence ranges from 0.06% to 5.8%. The majority of VBDs are asymptomatic. Downbeat nystagmus has been reported as a component of an infrequent ocular movement disorder in VBD. Nevertheless, oculopalatal tremor (OPT), delayed sequelae of a brainstem lesion, has never been demonstrated in VBD cases. Synchronized rhythmic involuntary contractions of the soft palate with an ocular pendular nystagmus, predominantly vertical pendular nystagmus, are the hallmark presentation. Our case demonstrated a 50-year-old female who presented with 3-month history of oscillopsia. Examination showed binocular conjugate torsional jerk nystagmus simultaneous with a contraction of the soft palate, defined as an atypical OPT, resulting from dolichoectatic left vertebral artery compressing on medulla, demonstrated by magnetic resonance imaging. Bilateral conjugate torsional jerk nystagmus simultaneous with palatal tremor, considering as an atypical OPT, should be included as one of the symptomatic presentations of vertebral artery dolichoectasia in spite of its rarity.