NEUROLOGYNEUROLOGY

DR.WALID REDA ASHOURDR.WALID REDA ASHOUR

LECTURER OF NEUROLOGYLECTURER OF NEUROLOGY

INTRODUCTIONINTRODUCTION

WHAT IS NEUROLOGY?

Neurology is the branch of medicine that

deals with diseases of the nervous system.

MAJOR DIVISIONSMAJOR DIVISIONS

NERVOUSNERVOUSSYSTEMSYSTEM

CENTRALCENTRAL NERVOUSNERVOUS SYSTEMSYSTEM

PERIPHERALPERIPHERALNERVOUSNERVOUSSYSTEMSYSTEM

CENTRAL NERVOUS SYSTEMCENTRAL NERVOUS SYSTEM

1. Cerebrum2. Brain stem3. Cerebellum

Intracranial part

Intracranial part

Spinal part

Spinal part

1- Spinal cord

2- Cauda equina

I- INTRACRANIAL PART

1- CEREBRUM

Two (2) cerebral hemispheres. Connected to:

1. Each other by CORPUS CALLOSUM.

2. Brain stem by CEREBRAL PEDUNCLES.

- Outer gray matter (cerebral cortex) contains certain areas with specific functions.

- Inner white matter composed of nerve fibers conducting impulses TO & FROM cerebral cortex

EACH cerebral hemisphere divided into :

FOUR ( 4 ) LOBES:

1. Frontal

2. Parietal

3. Temporal

4. Occipital

2- Brain stem

Formed of :

1- Midbrain

2- Pons

3- Medulla

Connected to:

1. Cerebral hemisphere

by cerebral peduncles

2. Cerbellum by cerebellar

peduncles

BRAIN STEM contains motor nuclei of cranial nerves:

• 3 & 4 in MIDBRAIN

• 5, 6 &7 in PONS

• 9, 10, 11 & 12 in MEDULLA

N.B. 1, 2 & 8

are sensory nerves have no motor nuclei

NAMES OF CRANIAL NERVES• 1 Olfactory

• 2 Optic

• 3 Oculomotor

• 4 Trochlear

• 5 Trigeminal

• 6 Abducent

• 7 Facial

• 8 Vestibulocochlear

• 9 Glossopharyngeal

• 10 Vagus

• 11 Accessory

• 12 Hypoglossal

CLASSIFICATION OF CRANIAL NERVES

• SENSORY : contain only sensory fibers1- Olfactory2- Optic

8- Vestibulocochlear • MOTOR : contain only motor fibers

3- Oculomotor 4- Trochlear 6- Abducent 11- Accessory

12- Hypoglossal • MIXED : contain both sensory and motor fibers

5- Trigeminal 7- Facial9- Glossopharyngeal 10- Vagus

Sensory cranial nerves

N. Name Function Assessment

1 Olfactory Smell Examination of smell

2 Optic Vision Acuity, field & fundus

8 Vestibular part

Equilibrium Caloric and rotational chair

Cochlear part

Hearing Watch test, Weber test

Motor cranial nervesN. Name Function Assessment

3 Oculomotor Motor to superior, inferior and medial recti; inferior oblique & levator palpebrae superioris

Ptosis, pupil, eye movements & squint

Parasympathetic to sphincter papillae and ciliary muscle

4 Trochlear Motor to superior oblique Look to opposite shoulder

6 Abducent Motor to lateral rectus Lateral eye movement

11 Accessory Motor to sternocleidomastoid and trapezius

Elevaton of shoulders and neck rotation

12 Hypoglossal Motor to muscles of tongue Tongue movements

Mixed cranial nervesN. Name Function Assessment

5 Trigeminal Muscles of mastication & sensations of face

Face sensations & power of muscles of mastication

7 Facial Muscles of facial expression & taste sensation in ant. 1/3 of tongue

Muscles of facial expression & taste sensation in ant. 1/3 of tongue

10 Vagus Sensation and movements of Larynx, pharynx, thoracic and abdominal organs

Palatal and pharyngeal reflexes & movements of uvula

9 Glossopharyngeal Taste in post 2/3 of tongue & gen. sensation

Taste & general sensation and pharyngeal reflex

3- CEREBELLUM

• Behind the brain stem

• Formed of : * Medline vermis

* Two cerebellar hemispheres

• Composed of :

Outer grey matter and inner

white matter

MBMB

PonsPons CC

MOMO

Superior peduncle connects cerebellum with MIDBRAIN. Middle peduncle connects cerebellum with PONS. Inferior peduncle connects cerebellum with MEDULLA

OBLONGATA

CEREBELLAR PEDUNCLES

LeftHemisphere

righthemisphere

CEREBELLAR HEMISPHERES AND VERMIS

Cerebellar Hemispheres are the two bilateral structures.Vermis is the unpaired midline structure between

the two hemispheres.

VERMIS

II- SPINAL PART

1- SPINAL CORD

• Inside spinal canal

• End at lower border of L1 vertebra.

• Its lowermost 3 segments S3,4,5 = Conus.

• The above 4 segments L4,5 & S1,2 = Epiconus.

• Inner grey matter (cells) surrounded by

white matter.

SPINAL CORD

SPINAL CORD TRACTS

• White matter contains ascending and descending nerve fibers (TRACTS):

1- ASCENDING• Lateral & Ventral spinothalamic.• Gracile & Cuneate.• Spinocerebellar.• Lissauer’s.

2- DESCENDING• Corticospinal (pyramidal).• Reticulospinal, vestibulospinal, tectospinal, rubrospinal &

olivospinal

2- CAUDA EQUINA

• Collection of LUMBOSACRAL ROOTS which fills the lower part of the spinal canal below L1 vertebra.

THE MOTOR SYSTEM

Motor pathway

UPPER MOTOR NEURON(pyramidal system)

* Originates in motor area 4 & premotor area 6

* Terminates at the anterior horn cells (AHCs)

of the different levels of the spinal cord.

* It supplies the opposite side of the body.

LOWER MOTOR NEURON

• Formed of AHCs & Peripheral motor nerves

(which transmit the motor impulses to the

voluntry muscles).

EXTRA PYRAMIDAL SYSTEM

• Originates from centers at various levels of CNS mainly the

BASAL GANGLIA.

• It controls the opposite side of the body.

CEREBELLAR SYSTEM

• Composed of Neo, Archi & Paleo- cerebellum.

• It co-ordinates the movements of the same side of the body.

UMNL LMNL

Tone Increased, with ‘clasp knife’ quality

Decreased

Clonus Present Absent Fasciculations Absent Present Muscle Wasting Absent, but disuse

atrophy eventually results

Present (within 2-3 weeks)

Tendon Reflexes Increased. Extensor plantar reflexes.

Decreased or absent. Flexor plantar reflexes.

Distribution Whole limbs, with more weakness in the upper limb extensors and lower limb flexors

Specific muscle groups affected (e.g. in the distribution of a spinal segment, or just the proximal muscles, etc.)

Thank you