Cranial nerves

  • Olfactory I
  • Optic II
  • Oculomotor III
  • Trochlear IV
  • Trigeminal V
  • Abducens VI
  • Facial VII
  • Vestibulocochlear VIII
  • Glossopharyngeal IX
  • Vagus X
  • Accessory XI
  • Hypoglossal  XII

Olfactory nerve (I)

Sensory nerve

Pathological conditions:

Anosmia  (conductive, sensorineural, and mixed)  

Hyposmia

Hyperosmia

Olfactory hallucinations

Dysosmia: a- cacosmia: usual smells feels as bad                             b- heterosmia: challenging to distinguish between different smells

Ethiologies (causes) of anosmia:

Infection

Inflammation: allergy, sarcoidosis

Sinus diseases: sinusitis, Wegener`s granulomatosis

Drugs: alpha-interferon

Toxic: alcohol, nicotine, aminoglycosides, zinc sulfate (through direct contact)

Degenerative nerve diseases: MS (multiple sclerosis), Parkinson`s disease

Peripheral nerve disorders

Syndrome/genetic: Kallmann syndrome, Turner syndrome, albinism

Nutritional: Vitamin A (Retinol) deficiency, zinc deficiency

Endocrine: hypothyroidism, diabetes mellitus, hypoadrenalism

Life style

Trauma: concussion (brain injury)

Intracranial hemorrhage (bleeding)

Physiological aging

Iatrogenic: surgical complication, tracheostomy

Etiologies (causes) of hyperosmia:

Migraine

Meningitis (inflammation of brain-protective membrane)

Drugs: anti-depressive

Optic nerve (II)

Sensory nerve

Pathological conditions:

Opticus neuritis (inflammation in optic nerve)

Optic nerve tumor:  opticus glioma (in the patient with neurofibromatosis type I)

Clinical manifestations:

Anopsia or anopia (visual field defect)

Hemianopsia (hemianopia)

Etiologies (causes) of anopsia:

Genetic diseases: Leber`s disease

Concussion

Intracranial tumors: craniopharyngioma, prolactinoma

Metabolic disorders: vitamin B12 deficiency

Increased intracranial pressure (ICP) 

Neurodegenerative disorders: multiple sclerosis (MS)

Inflammatory disorders: vasculitis

Malformations: septo-optic dysplasia

Psychogenic blindness/visual field defect

Oculomotor nerve (III)

Motor and parasympathetic (autonomic) nerve

Clinical manifestation:

Diplopia (double vision)

Ptosis (upper eyelid drooping)

Mydriasis (dilatation of pupil)

Benedikt`s syndrome

Weber`s syndrome

Etiologies (causes) of nystagmus (involuntary and repetitive movement of the eye):

Intracranial tumors (infratentorial/posterior fossa)

Severe vision loss (CVI, vitamin B12-deficiency, Leber`s disease)

Ear disorders (Meniere`s disease, benign paroxysmal positional vertigo)

Idiopathic nystagmus (usually benign)

Paraneoplastic (with a different type of cancer such as lung cancer)

Etiologies (causes) of ptosis: 

Aponeurotic: secondary to local inflammation (by contact lense)

Neurogenic: Horners syndrome, parasympathetic dysfunction (cranial nerve III)

Muscular: myasthenia gravis, eyelid myokymia, focal muscular dystrophy/muscular dysgenesis

Trauma

Intracranial tumor

Intracerebral hemorrhage

Trochlear nerve (IV)

Motor nerve

Pathological conditions:

Trochlear nerve paresis/palsy

Diplopia (double vision): vertical, torsional, oblique

Ethiologies (causes) of trochlear nerve paresis/palsy:

Cerebral infarction

Intracranial hemorrhage (bleeding)

Infection: borrelia, Herpes simplex

Multiple sclerosis

Aneurysm

Intracranial tumor

Trigeminal nerve (V)

Motor and sensory nerve

Pathological conditions:

Trigeminal neuropathy: paresthesia (numbness), hypoesthesia, motor difficulties (weak suck)

Trigeminal neuralgia: chronic pain disorder in the face (trigeminal nerve dermatome)

Trigeminal neurinoma: concomitant with neurofibromatois type I

Trigeminal neuralgia (TN):

Frontal, maxillary and mandibular

Clinical manifestations of trigeminal neuralgia:

Neurogenic pain: it may occur during shaving, brushing teeth, chewing, washing face, or exposure to the bright light or vibration

Ethiologies (causes) of trigeminal neuralgia:

Sinusitis ( both as a differential diagnosis and etiology of TN)

Vascular malformations: aneurysm

Intracranial tumor: acoustic neuroma

Intracranial hemorrhage

Infection: neuroborreliosis, herpes infections, other bacterial or viral infections

Multiple sclerosis

Paraneoplastic syndrome

VNS (vagus nerve stimulation)

Idiopathic (unknown cause/etiology)

Treatment of trigeminal neuralgia:

Treatment of the underlying cause 

Pharmacological treatment by Carbamazepine, Baclofen, Gabapentin, Lamotrigine

Abducens nerve (VI)

Motor nerve

Pathological conditions:

Abducens paresis/palsy: peripheral, nuclear, and supranuclear lesions

Clinical manifestations: 

Diplopia

Etiologies (causes) of abducens nerve paresis/palsy:

Increased intracranial pressure (ICP)

Intracranial tumor

Intracranial hemorrhage

Cerebral infarction

Vascular malformation: aneurysm

Trauma

Complicated otitis

Inflammation/infection

Idiopathic (unknown cause/etiology)

Facial nerve (VII)

Motor, sensory and parasympathetic (autonomic) nerve

Pathological condition:

Facial nerve paresis/palsy

Hemifacial spasm

Clinical manifestations:

Paralysis of different muscles in the face

Lack of taste

Decreased secretion in the nose and mouth

Decreased salivary secretion

Etiologies (causes) of facial nerve palsy:

Trauma

Infektion: herpes, Ramsay-Hunts syndrome (HZV-infektion), borrelia

Iatrogenic

Intracranila tumor: acoustic neuroma

Idiopathic (Bell`s palsy)

Moebius syndrome

Vestibulocochlear nerve (VIII)

Sensory nerve

Pathological conditions:

Vestibular neuritis: dizziness, vertigo, headache, nausea, vomiting, balans difficulties

Acoustic neuroma: hearing loss, vertigo, balance difficulties (increased risk for acoustic neuroma in patients with neurofibromatosis type II)

Etiologies (causes) of vestibular neuritis:

Infection: bacterial or viral

Chronic otitis media

Glossopharyngeal nerve(IX)

Sensory, parasympathetic, and motor nerve

Pathological conditions:

Glossopharyngeal nerve paresis/palsy

Glossopharyngeal neuralgia

Glossopharyngeal neuroma: increased risk for a glossfopharyngeal neuroma in patients with neurofibromatosis type I

Clinical manifestations:

Glossopharyngeal neuralgia: paroxysmal pain in tonsils, middle ear, the back part of the tongue, soft palate, and pharynx

Glossopharyngeal neuroma: dysphagia, loss of taste in the back of the tongue, loss of feeling in the back of the pharynx

Most often, together with the involvement of cranial nerves, no. VIII and X

Etiologies (causes) of glossopharyngeal nerve paresis/palsy:

Trauma

Iatrogenic: surgical complication

Cerebral infarction: brain stem infarction

Moebius syndrome

Arnold-Chiari malformation

Vagus nerve (X)

Motor, sensory and parasympathetic nerve

Pathological conditions:

Vagus nerve pares/palsy

Clinical manifestations:

Dysphagia

Respiratory difficulties

Apnea (bilateral palsy of the recurrent laryngeal nerve)

Cardiac arrhythmia

Etiologier/orsaker till vagus nerve paresis/palsy: 

Tumor: tumor in posterior fossa

Inflammation:

Infektion: difteri

Mediastinal tumor: thymoma, lymphoma

Iatrogenisk: surgical complication (cardiac surgery)

Cerebral infarction

Accessory nerve (XI)

Motor nerve

Pathological conditions:

Accessory nerve paresis/palsy

Sandifer`s syndrome (combination of torticollis and gastroesophageal reflux)

Collet-Sicard syndrome: Involves the lower cranial nerves (IX, X, XI, and XII)

Clinical manifestations:

Torticollis

Anterocollis

Laterocollis

Retrocollis

Etiologies (causes) of accessory nerve paresis/palsy:

Trauma

Iatrogenic: lymph node biopsy, neck surgery

Tumor: tumor in posterior fossa and neck

Arnold-Chiari malformation

Syringobulbia (syrinx in the brain stem)

Cerebral infarction

Infection: poliomyelitis

Hypoglossal nerve (XII)

Motor nerve

Pathological conditions:

Hypoglossal nerve pares/palsy:

Clinical manifestations:

Lingual atrophy (atrophy of the tongue)

Abnormal tongue movements 

Tongue fasciculations

Ethiologies (causes)  to hypoglossal nerve paresis/palsy:

Tumor: Brain tumor in the posterior fossa 

Arnold-Chiari malformation

Syringobulbia (syrinxes in the brain stem)

Amyotrophic lateral sclerosis (ALS)

Cerebral infarction