Relevant terms and definitions: 1. Pure tone: A single frequency sound 2. Audiometer: Equipment used to generate pure tones of varying frequency and loudness and control their presentation 3. Air conduction (AC) threshold: lowest level dB HL (hearing threshold) at which the subject perceives 50% of pure tones introduced via earphones or speakers…
Tag: Nervous system

Pathological reflexes – Variations of Babinski
Normally, the pathological reflexes are not evident because they are suppressed by cerebrum at brainstem or spinal cord level by 6 months of age. Importance: Up-going (dorsiflexion) toe can be elicited at various sites and all indicated Upper Motor Neuron (UMN) lesion. Use a blunt-pointed object like fingernail or tip…

Meningeal signs
Meningitis refers to the inflammation of leptomeninges and underlying subarachnoid cerebrospinal fluid (CSF). Meningism or meningismus is a morbid state characterized by a meningitic syndrome (a triad of headache, photophobia and nuchal rigidity) without intracranial inflammation. Some authors, have also used the term “meningism” or “meningismus” to describe the characteristic signs…

Headbanging Injuries
It all began in a tour of Led Zeppelin – the craftsmen of one of the most popular rock songs of the past 40 years – “Stairway to Heaven”. The audience on the front row were nodding their heads against the rhythm of their music and that was when the…

Facial Nerve Anatomy
SYNONYMS: Cranial nerve seven (VII), Nervus facialis Supranuclear pathways 1. Somatomotor cortex: controlling motor component of facial nerve lies in precentral gyrus (Broadmann area 4,6,8) 2. Volitional component: Corticonuclear tracts descend and cross to supply both ipsilateral and contralateral facial (mainly to the contralateral side) nucleus i.e. frontal branch components…

Autonomous Sensory Zones of Peripheral Nerves
Synonym: Autonomous area Definition: These are the regions where single nerve roots supply distinct and non-overlapping areas of skin. By their nature the “autonomous zones” represent only a small portion of any dermatome and only a few nerve roots have such autonomous zones. The size of autonomous zone for a…
Surgical landmarks for identification of facial nerve in Parotid surgery
The facial nerve (CN VII) exits the skull base through the stylomastoid foramen situated posterolaterally to the styloid process and anteromedially to the mastoid process and enters the parotid gland to divide it into a large superficial lobe and a small deep lobe. The main trunk of facial nerve enters…
A Case of Neuroleptic Malignant Syndrome: A Quick Approach
A 15 year girl started complaining of strange feelings 3 weeks back. She started behaving weirdly and complained her mother that she could hear inanimate objects talking to her- like bangles, rings, glasses. She rapidly had a deterioration with change in personality. She starting acting bizarre and doing abnormal things….