The Importance of Measuring Mamillopontine Distance as a Diagnostic Criterion of Hydrocephalus Degrees

Spontaneous Intracranial Hypotension: Case Report and Update on Diagnosis and Treatment

Spontaneous intracranial hypotension (SIH) is an important cause of daily headaches that occur in young and middle-aged, active persons and is often misdiagnosed, leading to prolonged inactivity and rather high healthcare expenditures. Its diagnosis requires a high degree of clinical suspicion and careful interpretation of imaging studies. We present a case of SIH, which was successfully treated but which posed serious diagnostic challenges, ranging from cerebro-vascular disease and meningitis to granulomatous diseases, and for whom every therapeutic attempt just worsened the patient's condition until we finally reached the correct diagnosis. To raise awareness of this condition, we also present an updated overview of the clinical picture, evaluation, and treatment options for SIH.

Choroid plexus mast cells drive tumor-associated hydrocephalus

Tumor-associated hydrocephalus (TAH) is a common and lethal complication of brain metastases. Although other factors beyond mechanical obstructions have been suggested, the exact mechanisms are unknown. Using single-nucleus RNA sequencing and spatial transcriptomics, we find that a distinct population of mast cells locate in the choroid plexus and dramatically increase during TAH. Genetic fate tracing and intracranial mast-cell-specific tryptase knockout showed that choroid plexus mast cells (CPMCs) disrupt cilia of choroid plexus epithelia via the tryptase-PAR2-FoxJ1 pathway and consequently increase cerebrospinal fluid production. Mast cells are also found in the human choroid plexus. Levels of tryptase in cerebrospinal fluid are closely associated with clinical severity of TAH. BMS-262084, an inhibitor of tryptase, can cross the blood-brain barrier, inhibit TAH in vivo, and alleviate mast-cell-induced damage of epithelial cilia in a human pluripotent stem-cell-derived choroid plexus organoid model. Collectively, we uncover the function of CPMCs and provide an attractive therapy for TAH.

Normal measurements of brainstem and related structures for all ages: An MRI-based morphometric study

Background

Knowledge of the normal size of the brain stem and certain related structures play an important role in diagnosis of aging and neurodegenerative conditions affecting the brain. There is no well-established normative data for development and age-related changes pertaining to the brain stem and related structures in the Indian context. The objective of this study was to assess various linear and angle measurements of the brain stem, cerebral peduncles, middle cerebellar peduncles, and proximal cervical cord for all ages in patients who have undergone MRI brain for unrelated pathologies.

Methods

A record-based retrospective cross-sectional and analytical study. T1WI axial and sagittal images were studied for the following variables: Cerebral peduncle transverse thickness, Interpeduncular angle, Middle cerebellar peduncle transverse thickness, Ventral midbrain anteroposterior thickness, Midbrain height, Mamillopontine distance (MPD), Pontomesencephalic angle (PMA), Pons anteroposterior thickness, Medulla anteroposterior thickness and Spinal cord anteroposterior diameter.

Results

Significant differences (p = 0.001) were observed in nearly all the variables among various age groups. Males demonstrated significantly higher mean values (at 5% level of significance) for a majority of the variables. Most of the variables measured, e.g. Cerebral peduncle, Middle cerebellar peduncle, Ventral midbrain thickness, Midbrain height, Pons, Medulla, and Spinal Cord diameter, showed a steady and sharp increase in values from infancy and reached maximum values during the third decade, followed by a variable degree of decline in values.

Conclusion

Magnetic Resonance Imaging (MRI) morphometry of brainstem and related structures is easily doable and is also reproducible. Present study lays down normative data for the brainstem and certain related structures for all ages, which can be referred to in day-to-day practice.