Brainstem
Absent vestibulo-ocular (caloric) responses are part of the brainstem death tests.
What our notes say
- Absent vestibulo-ocular (caloric) responses are part of the brainstem death tests. (Paediatrics end of fourth year main exam: 1 July 2019, Paper One, 99 of 100 MCQs)
- If a cranial nerve deficit is on the opposite side to a hemiparesis, the lesion is at the level of that nerve's nucleus (brainstem). (CNS History Taking & Neurological Exam Guide | Clinical Skills)
- Mechanism of action: toxin binds to gangliosides at the neuromuscular junction, is taken up and transported retrograde along the axon to the CNS, then travels via cranial nerve/cranial pathway transsynaptically to reach the spinal cord/brainstem (Streptococcus Classification, S. pyogenes, Rheumatic Fever, AGN)
- Duret hemorrhages — linear/flame-shaped hemorrhages in the midline and paramedian midbrain/pons, caused by distortion or tearing of penetrating vessels supplying the upper brainstem (Cerebral Edema, Hydrocephalus, Raised ICP & Brain Herniation Pathology)
- It interacts with the motor system at multiple levels (spinal, brainstem, cortex), not only at the cortex. (cat 2 2014 — Source Paper Awaiting Edit)
- Regions most involved include the basal ganglia, cerebellum, thalamus, hypothalams, and brainstem. (CNS PATHOLOGY — Past Paper Questions & Answers)
Study material on Brainstem
- MEDICAL PHYSIOLOGY II ESsays
- Sleep Physiology Examination Paper
- cat 2 2014 — Source Paper Awaiting Edit
- CNS Pathology: Neuron & Astrocyte Injury, Reactions & Neurodegeneration
- CNS History Taking & Neurological Exam Guide | Clinical Skills
- EXAM: Vaccines & Antivirals, Rabies, CMV & EBV, Adenovirus & Enteroviruses
- CNS Malformations: NTDs, Spina Bifida & Anencephaly Guide
- CNS Trauma Neuropathology: Fractures, Concussion & CTE
- Neurodegenerative Prion Diseases: CJD, Pathology & Rapid Dementia
- Master First-Year Anatomy: Must-Know Essays & Key Concepts
Images
Practice questions on Brainstem
Which structure is an important pathway for communication between the limbic system and the brainstem?
- Mamillothalamic tract
- Fornix
- Anterior commissure
- Indusium griseum
- Medial forebrain bundle
Answer: E. The medial forebrain bundle is a major pathway connecting limbic structures to the brainstem, particularly the hypothalamus. It carries both ascending and descending fibers and is important for emotional and motivational behaviors. The other structures have different functions and connections within the limbic system. ---