Category Archives: Neurological Diseases and Diseases of Voluntary Muscle

Epilepsy and other causes of recurrent loss of consciousness

EPILEPSY An epileptic seizure is a convulsion or transient abnormal event experienced by the subject due to a paroxysmal discharge of cerebral neurones. Epilepsy, by definition, is the continuing tendency to have such seizures, even if a long interval separates attacks. A generalized convulsion or grand mal fit is the commonest recognized event. INCIDENCE Epilepsy is a common condition. Some 3% of the populati

Unconsciousness and coma

The central reticular formation, which extends from thebrain stem to the thalamus, influences the state of arousal. This complex process involves interactions between the reticular formation, the cortex and brain stem, and all sensory pathways. Disturbed consciousness Definitions CONSCIOUSNESS means awareness of oneself and  he surroundings in a state of wakefulness. CLOUDING OF CONSCIOUSNESS is reduced wakefu

The general principles of pain management

The management of chronic pain depends on reaching a diagnosis as to the cause of the pain by a detailed history, examination and the appropriate use of investigations. A treatment plan has several components: 1 Psychological. The appreciation of pain is always subjective.  A hronic pain may profoundly influence apatient’s life-style. Depression is almost universally  associated with chronic benign pain,

The sensory system

Peripheral nerves and spinal roots Peripheral nerves carry all modalities of sensation from either free or specialized nerve endings to the dorsal root ganglia and thus to the cord. The sensory distribution of the spinal roots (dermatomes) is shown in Fig. 18.10 The spinal cord Posterior columns For clinical purposes, the sensory modalities of vibration sense, joint position, light touch and two-point discrimi

LOWER MOTOR NEURONE LESIONS

The LMN is the motor pathway from the anterior horn cell (or cranial nerve nucleus) via a peripheral nerve to the motor end plate. The motor unit consists of a single anterior horn cell, the single fast-conducting a motor nerve fibre that leaves the spinal cord via the anterior root, and the group of muscle fibres (100-2000) being supplied via the mixed peripheral nerve. Anterior horn cell activity is modulat

The motor system

THE CORTICOSPINAL TRACTS The corticospinal tracts originate from the neurones of the fifth layer of the cortex and terminate on the motor nuclei of the cranial nerves and anterior horn cells of the spinal cord. The pathways of importance (Fig. 18.8) in clinical diagnosis decussate in the medulla and pass to the contralateral halves of the cord as the crossed lateral corticospinal tracts. This is the ‘pyr

THE GLOSSOPHARYNGEAL AND VAGUS NERVES (NINTH AND TENTH CRANIAL NERVES)

The glossopharyngeal nerve This mixed nerve arises in the medulla and leaves the skull through the jugular foramen with the vagus and accessory nerves. Its sensory fibres supply all sensation to the tonsillar fossa and pharynx (the afferent pathway of the gag reflex), and taste to the posterior third of the tongue. Motor fibres supply the stylopharyngeus muscle, autonomic  fibres supply the parotid gland, an

Meniere’s disease

This condition is characterized by recurrent attacks of the three symptoms-vertigo, tinnitus and deafness. It is associated with a dilatation of the endolymph system of unknown cause. SYMPTOMS The sudden, unprovoked attacks of vertigo with vomiting and loss of balance last from minutes to hours. Tinnitus and deafness accompany an attack but may be overshadowed by the degree of vertigo. The attacks are recurre

THE VESTIBULOCOCHLEAR NERVE (EIGHTH CRANIAL NERVE)

This nerve has two parts-cochlear and vestibular. Cochlear nerve Auditory fibres from the spiral organ (of Corti) in the cochlea pass to the cochlear nuclei in the pons. Fibres from these nuclei cross the midline and pass upwards through the medial lemnisci to the medial geniculate bodies and the temporal gyri. The symptoms of a cochlear nerve lesion are deafness and tinnitus. The signs are of hearing loss,

THE FACIAL NERVE (SEVENTH CRANIAL NERVE)

This nerve is largely motor in function, supplying the muscles of facial expression. The nerve carries sensory taste fibres from the anterior two-thirds of the tongue via the chorda tympani. The complex arrangement of the nerves to the face, their nuclei and connections. The facial nerve arises from the seventh nerve nucleus in the pons and leaves the skull through the stylomastoid foramen. Part of each facia