Role of diffusion tensor imaging in the evaluation of white matter integrity in idiopathic intracranial hypertension.

OBJECTIVES: To determine whether idiopathic intracranial hypertension (IIH) may affect white matter integrity and optic pathways by using diffusion tensor imaging (DTI) and to correlate the DTI metrics with intracranial pressure (ICP). METHODS: This study is a retrospective case-control study. A total of 42 patients who underwent lumbar puncture and those with elevated ICP, meeting the diagnostic criteria for IIH, were included in the study. All patients had supportive magnetic resonance imaging findings for the diagnosis of IIH. The headache control group comprised 36 patients who presented to the Neurology Department with infrequent episodic tension-type headache, had a normal neurologic examination, and had clinical and radiological findings suggestive of normal ICP. For each patient with IIH, clinical findings and ophthalmological measurements were recorded. The apparent diffusion coefficient (ADC), fractional anisotropy (FA), axial diffusivity (AD), and radial diffusivity (RD) values were calculated using a region of interest-based method in different white matter tracts and optic pathways and compared. RESULTS: A total of 42 patients diagnosed with IIH (three males, 39 females), with a mean (standard deviation [SD] age of 38.1 (8.9) years), and 36 headache controls (10 males, 26 females, mean [SD] age; 38.1 [9.4] years) were included in the study. The mean (SD) body mass index (BMI) of the patients with IIH was 25.2 (1.9) kg/m2, and the mean (SD) BMI of the headache controls was 23.3 (1.5) kg/m2 (p < 0.001). Decreased FA values and increased RD values in the cingulum were detected in patients with IIH compared to the headache controls (p = 0.003, Cohen's d = 0.681; p = 0.002 Cohen's d = -0.710). Decreased AD values in the left and right superior cerebellar peduncle and increased ADC values in the middle cerebellar peduncle were detected in patients with IIH compared to the headache controls (p < 0.001, Cohen's d = 0.961; p = 0.009, Cohen's d = 0.607; p = 0.015, Cohen's d = -0.564). Increased ADC and RD values and decreased FA values in optic nerve were detected in patients with IIH (p = 0.010, Cohen's d = -0.603; p = 0.004, Cohen's d = -0.676; p = 0.015 Cohen's d = 0.568). A positive correlation was found between the cerebrospinal fluid pressure and ADC values of the left and right superior and left inferior longitudinal fasciculus, genu of the corpus callosum, and right optic radiation (r = 0.43, p = 0.005; r = 0.31, p = 0.044; r = 0.39, p = 0.010; r = 0.35, p = 0.024; r = 0,41, p = 0.007). There was a positive correlation between the retinal nerve fiber layer thickness and the ADC values of the optic nerve (r = 0.32, p = 0.039). CONCLUSIONS: Intracranial hypertension can be associated with deteriorated DTI values, which might be interpreted as a sign of impaired white matter microstructural integrity in many brain regions beyond the periventricular white matter. Pressure-induced edema and axonal degeneration may be the potential underlying mechanisms of this microstructural damage.

Non-invasive estimation of cerebrospinal fluid pressure in idiopathic intracranial hypertension: magnetic resonance imaging analysis of optic nerve and eyeball.

PURPOSE: Invasive methods such as lumbar puncture and intraventricular catheters are commonly used to measure intracranial pressure (ICP). This study aims to develop quantitative and non-invasive techniques to measure ICP in patients with Idiopathic Intracranial Hypertension (IIH) using magnetic resonance imaging (MRI) findings. METHODS: MRI data obtained from 50 patients with IIH and 30 age- and sex- matched controls were analyzed and optic nerve sheath diameter (ONSD), eyeball transverse diameter (ETD) and optic nerve diameter (OND) were measured. ONSD, ONSD/ETD and OND/ONSD indexes were calculated according to different ONSD measurement distances. Correlations of MRI findings with ICP were calculated. Sensitivity and specificity of all methods were analyzed. RESULTS: ONSD and ONSD/ETD index at 3 mm and 10 mm behind the eyeball were significantly higher (p < 0.001) and OND/ONSD index at 3 mm behind the eyeball was significantly lower (p < 0.001) in the IIH group. The ONSD/ETD index at 3 mm had the highest area under the curve (AUC) value (0.898) with a cut-off of 0.27 mm (82% sensitivity and 91.67% specificity) for predicting high cerebrospinal fluid (CSF) pressure, followed by ONSD measurements at 3 mm (AUC = 0.886) with a cut-off of 6.17 mm (83% sensitivity and 86.67% specificity). The OND/ONSD index at 3 mm posterior to the eyeball decreased significantly as ICP increased, and the strength of the relationship was moderate (p < 0.001; r = -0.358). CONCLUSIONS: ONSD and ONSD/ETD index measured on MRI sequences are potentially useful in detecting elevated ICP. The OND/ONSD index correlates with CSF pressure and these techniques may be helpful in diagnosing IIH.

Evaluating the accuracy and readability of ChatGPT in providing parental guidance for adenoidectomy, tonsillectomy, and ventilation tube insertion surgery.

OBJECTIVES: This study examined the potential of ChatGPT as an accurate and readable source of information for parents seeking guidance on adenoidectomy, tonsillectomy, and ventilation tube insertion surgeries (ATVtis). METHODS: ChatGPT was tasked with identifying the top 15 most frequently asked questions by parents on internet search engines for each of the three specific surgical procedures. We removed repeated questions from the initial set of 45. Subsequently, we asked ChatGPT to generate answers to the remaining 33 questions. Seven highly experienced otolaryngologists individually assessed the accuracy of the responses using a four-level grading scale, from completely incorrect to comprehensive. The readability of responses was determined using the Flesch Reading Ease (FRE) and Flesch-Kincaid Grade Level (FKGL) scores. The questions were categorized into four groups: Diagnosis and Preparation Process, Surgical Information, Risks and Complications, and Postoperative Process. Responses were then compared based on accuracy grade, FRE, and FKGL scores. RESULTS: Seven evaluators each assessed 33 AI-generated responses, providing a total of 231 evaluations. Among the evaluated responses, 167 (72.3 %) were classified as 'comprehensive.' Sixty-two responses (26.8 %) were categorized as 'correct but inadequate,' and two responses (0.9 %) were assessed as 'some correct, some incorrect.' None of the responses were adjudged 'completely incorrect' by any assessors. The average FRE and FGKL scores were 57.15(±10.73) and 9.95(±1.91), respectively. Upon analyzing the responses from ChatGPT, 3 (9.1 %) were at or below the sixth-grade reading level recommended by the American Medical Association (AMA). No significant differences were found between the groups regarding readability and accuracy scores (p > 0.05). CONCLUSIONS: ChatGPT can provide accurate answers to questions on various topics related to ATVtis. However, ChatGPT's answers may be too complex for some readers, as they are generally written at a high school level. This is above the sixth-grade reading level recommended for patient information by the AMA. According to our study, more than three-quarters of the AI-generated responses were at or above the 10th-grade reading level, raising concerns about the ChatGPT text's readability.

MR Features of Varicella-zoster Myelitis in an Immunocompetent Patient.

BACKGROUND: Varicella-zoster virus (VZV) is a latent virus that can remain in the central nervous system. Reactivation of the virus can cause some neurologic manifestations, and myelitis is one of the rarest of them. In this report, we aimed to present the MRI features of long-segment cervical myelitis after VZV infection, which is rarely reported in the literature. CASE PRESENTATION: A 69-year-old patient, who was diagnosed with varicella-zoster two months ago and treated with valacyclovir, was admitted to our clinic with worsening of his complaints and weakness in the right upper extremity. Neurological examination was normal in the left upper and bilateral lower extremities, but the muscle strength in the right upper extremity was evaluated as 4/5 grade. While rare leukocytes (10 leukocytes/mm³, 50 erythrocytes/mm³, high protein level (46 mg/dl, ref.15- 40 mg/dl)) were seen in the cerebrospinal fluid (CSF) analysis, no microorganisms were seen, and no growth was observed in the culture. VZV antibody-immunoglobulin G (Ab-IgG) was positive in CSF, while polymerase chain reaction [PCR] for VZV was negative. On cervical MRI, lesions showing T2 hyperintensity were observed from the C3-4 level to the C7-T1 level, eccentrically located in the right paramedian spinal cord. On post-contrast images, patchy heterogeneous contrast enhancement was noted in these regions of the spinal cord. When the patient's history, CSF features and MRI examinations were evaluated together, the lesions were consistent with VZV myelitis. The patient was started on valacyclovir treatment, and during the follow-up, the patient's complaints decreased, while no progress was observed in neurologic symptoms. CONCLUSION: As a result, we aimed to report the MRI features of this rare complication of varicellazoster and emphasize the necessity of keeping this in mind in the etiology of myelitis, especially in cases with patchy enhancement, to achieve early diagnosis and treatment.

Evaluation of white matter integrity by diffusion tensor imaging in the deficiencies of vitamin B12 and folate in older patients.

OBJECTIVES: The aim of this study is to investigate whether white matter (WM) integrity is impaired in vitamin B12 and folate deficiency with Diffusion Tensor Imaging (DTI) in older patients. METHODS: All the patients aged ≥65 years admitted to the geriatric clinic and performed DTI-MRI were included in the study. DTI parameters (fractional anisotropy, mean diffusivity, axial diffusivity, radial diffusivity) were calculated by ROI-based method in white matter tracts. Deficiency threshold for vitamin B12 were defined as <200 pg ml-1 and <400 pg ml-1 separately; and for folate as <3 ng ml-1 and <6 ng ml-1, separately. RESULTS: DTI was performed to older patients having serum vitamin B12 level (n = 106, mean age = 80.7±7.7, 66% female) and folate level (n = 101, mean age = 80.7±7.5, 67.3% female). Significantly lower FA and higher MD and RD levels were observed in multiple WM areas including superior and middle cerebellar peduncles, cingulum and genu of corpus callosum in patients with vitamin B12 <400 pg ml-1 (p < 0.05). DTI indices also showed significant changes in the genu of corpus callosum, and right and left superior longitudinal fasciculus in patients with folate <6 ng ml-1 (p < 0.05). CONCLUSIONS: Deficiencies of vitamin B12 and folate may be associated with impaired white matter integrity in elderly even at high laboratory levels, and DTI is a useful method to detect it. ADVANCES IN KNOWLEDGE: Early detection of impaired WM integrity caused by micronutrient deficiencies poses a great significance in terms of prevention and intervention, and DTI is an effective non-invasive method to be used for this purpose.