Thorough Neurological Examination- All in One Page

Never ever presume a neurological diagnosis without interacting with a patient and just by seeing the radiology report or just by listening the patient's complaints. Examine a patient without any presumption & bias, You will always feel rewarded.
Listen to the patient. Patient is the best guide and will provide you the important clue for the diagnosis. History taking is an opportunity to interact with people from diversified background. 
While taking history of a patient who is suspected to have a neurological disorder it should always be prudent to take history pertaining to lesions of brain, spinal cord and peripheral nerves. In this manner you can complete and cover the entire central and peripheral nervous system.
So, if you suspect a lesion of the cerebral hemisheres, History of Seizure, Headache, Vision and , Deterioration of conscious level or loss of consciousness, Weakness of the face or limbs should be taken into detail. 
If you suspect a lesion of cerebellum, then history of imbalance, ataxia and difficulty in walking should always be taken.
And if you suspect a lesion of the brain stem ( Midbrain , pons, medulla Oblongata), the symptoms of multiple cranial nerve deficits ( speech abnormality, nystagmus, difficulty in deglutition, loss of Gag reflex),  and long tract signs ( weakness in limbs, hyperrelexia, increased tone in limbs, positive Babinski sign) are expected.
In patients with lesions of the spinal cord history must include details about  weakness of the limbs, bladder and bowel involvement.

History of headache must include Onset ( sudden, gradual), Site ( holocranial, hemicranial , temoral)Frequency, duration, severity, Character ( Aching, throbbing), timing ( e.g., morning , evening), Precipitating factors (coughing, strenuous work) , Relieving factors ( analgesics, rest) , Associated features ( nausea, vomiting, visual disturbance).
History of Visual Disorder should include onset, frequency, impairment ( uniocular or both eyes, partial or total), diplopia, Precipitaing factor, Associated features
History of Loss of Consciousness may be due to syncope because of cardiac causes or vasovagal shock or due to neurological causes like a part of seizure or neurotrauma or a space occupying lesion in the brain. Loss of consciousness may also be due to low blood sugar level in a patient on diabetic treatment or alcohol or drug abuse.
Speech disorder may be a difficulty in Articulation or Expression or Understanding.
Weakness in the limbs may be Quadriparesis, Hemiparesis or Monoparesis with or without involvement of facial muscles.
History of Sensory system abnormalities  may expressed by the patient as Numbness, feeling of crawling of ants or insects, Tingling or inability to feel a part of the body.
History of cranial nerve deficits may be expressed by the patient as inability to smell, inability to read, loss of vision, diplopia, frequent changes of spectacle, partial closure of the eyelid ( Ptosis)loss of sensation over the face, drooling of saliva from the side, difficulty in closing eye, slurring of speech or change in voice, difficulty in hearing or Deafness, Tinnitus, Vertigo or Dizziness, inability to swallow, inability to shrug and turn face and inability to protrude tongue.

Neurological examination is straight forward, It is like substraction and addition of numbers, like 2+2=4. So, if there is right hemiparesis of body and face and the deep tendon reflexes are increaded, there must be some lesion on the left side of the brain. There is nothing wrong in rechecking the neurological examination findings. But, be sure of your neurological examination findings. Your examination may have a great impact on clinical outcome and plan of the treatment. In Neuroscience most of the things are evident. As students we used to think that many things may be theortical. But, with the advent of newer and advanced neuroradiology, microneurosurgery and functional neurosurgery, lot of procedures are now based on physiological and neuroanatomical localization.
One should begin with systemic examination. See Pallor ( anemia), Icterus ( jaundice), Lymhadenopathy. Anemia may explain many symptoms. Lymhadenopathy may indicate infection, lymphoma or metastasis.

Examine Pulse:  Bradycardia is an omnious sign of raised intrcranial pressure ( ICP)
                           Irregular Pulse may indicate syncope
Blood pressure :  Hypertension may indiacte raise ICP
Respiratory Rate: Irregular Respiration, Bradycardia and Hypertension are parts of Cushing reflex which is due to raised ICP.
Neck rigidity may indicate meningitis or subarachnoid hemorrhage. Restriction of neck movement may be due to cervical spondylosis. One should be very careful while examining a patient with head injury. if a patient is unconscious and his GCS is 8 or less, it is presumed that there may be associated cervical spine injury. So, in severely head injured patient , neck should be immobilized by putting a cervical collar while shifting the patient
Neurological examination begins with higher mental function. orientation to time, place and person should be asked.
cranial nerve examination: Soap may be used to examine olfaction. Vision should be seen in both eyes. If patient is unable to count fingers, then perception of light should be examined with a torch. Pupillary light reflex,ie, constrction of both the pupils when light is projected in eye , gives a clue about both second and third cranial nerves. because second cranial nerve (Optic Nerve) is afferent and third cranial nerve ( Occulomotor nerve) is efferent of this light reflex. Although this is very simple examination but it has great value. We often presume that vision is normal and miss it. A child with craniopharyngima, an adult  with  clinodal meningima or pituitary adenoma may not have any vision in one eye but even patiets or their parents may not be aware about the uniocular visual loss. So, if a doctor misses this finding, there may be catastrophic consequences. As immediately following the surgery , there is natural tendency in everyone to check the vision and it could be concluded that this visual loss be due to surgery. Optic nerve tumor, optic nerve injury, retinal detachmentmay also present with uniocular visual loss.
3,4,6 cranial nerves function may be examined by seeing the conjugate eye movements of both eyes together.
5th cranial nerve, 7th cranial nerve is by examining the face. sensation over the face is mainly by the Vth cranial nerve ( Trigeminal nerve). There are three sensory divisions of Trigeminal nerve ( V1, V2, V3). 7th cranial nerve is the motor supply to the face.
Hearing is through 8th cranial nerve. Ideally 8th cranial nerves should be examined by Tuning forks. If patient hears the rubbing of fingers of the examiner close to each ear, it may give some clue to the intact hearing.
If the gag reflex is intact, 9th and 10th cranial nerves are intact. 
Patient is asked to Shrug the shoulder and turn the face against the resistance to examine sternocleidomastoid and trapezius muscle which are suppled by the spinal accessory nerve.
Protrusion of tongue is possible with the 12th cranial nerve. If Hypoglossal nerve is damaged the tongue deviates to the injured side on protruding. 
Sensory nervous examination should be done before motor examination. Because patients usually are cooperative and sensory system examination is subjective and needs patient,s cooperation.
Motor examination : Movement of all four limbs. Power in all four limbs should be checked separately and should be compared with your own strength. Deep tendon reflexes and tone should also be examined.
Gait; If a patient is able to walk, gait should alsio be examined to complete the thorough neurological examination 

Neuron, Development of Brain

A single neuron is the basic functional unit of the nervous system. It is like a brick in a house. As house is made up of many bricks similarly brain is made of a billion neurons. As cement is needed to provide strength , similarly the neurons are strengthened by neuroglia cells.

A single neuron has has s body (which is also known as soma) with nucleus. Inside  the body there are Nissl granules. From the body arise many projections which carry impulses to the body of the neuron, these tiny projections are called Dendrites ( look like branches of a tree). From the3 body or soma of the neuron a long Axon emerges. The junction of the body and axon is called Axon hillock. Signal and material from the body travel through the axon. Most of the axons are myelinated , i.e., axons are usually covered by a sheath of myelin. In the peripheral nervous sytem myelin is formed by Schwann cells and in the brain it is formed by Oligodendrocytes ( glia cells). This myelin provides white colour and the area of the brain where large number of myelinated fibres are present is called white matter. There are gaps in the myelin sheath along the entire length of axon, these gaps are known as Nodes of Renveer, which allows fast movement of electrical impulses ( action potentials) along the axon. At distal end axon synapses with other neuron or muscle fibre.

This image is a simple depiction to show the development of the brain. 

The brain arises from a tube which is known as neural tube in an embryo. 

In the early embryonic stage of development there are three layers , endoderm, mesoderm and ectoderm. 

Ectoderm is the outer layer of the embryo. Some of the ectoderm cells which are present in the center become destined to form  neural ectoderm. These cells invaginate and convert into a tube which is now, known as Neural tube which is open at both the ends, also known as anterior and posterioral neuropore.

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After 3rd week of embryo development cranial opening of the neural tube which is also known as anterior neuropore , closes. Any abnormality of the closure of the this end may lead to congenital birth anomaly of the brain like anencephaly.

The posterior or caudal neuropore closes at the end of 4th week of embryonic development. Abnormality of the closure of posterior neuropore may lead to spina bifida, split cord malformation. This fact is very significant because when a female becomes aware that she is pregnant most of the neural tube is already developed . A flic acid or folate deficiency has been known to cause neural tube defects, that is why, folate supplementation is advocated in females who plan a pregnancy.

To repeat it again,  brain arises from a tube which is known as neural tube in an embryo. A tube is shown in the diagram mentioned above.

Then the anterior or cranial end of this tube is expanded into three parts which form the brain and caudal or elongated part forms the spinal cord. The three segments of the cranial part of the neural tube are destined to form three major part of the brain. Forebrain, midbrain and hindbrain.

Three cranial expansions are : Prosencephalon ( Forebrain), Mesencehalon (Midbrain) and Rhombencephalon ( Hindbrain). Remember nemonic for 3 sementation stage: PMR. Cavities inside these structures form the ventricles.

Later there are further subdivisions and it becomes of five segments.

Prosencephalon divides into two ;  Telencephalon and Diencephalon. Telencephalon later transforms into two cerebral hemispheres and its cavities become lateral ventricles. Diencephalon may be simply imagined to be like a box , the cavity iside becomes Third ventricle. he lateral walls of this box become 2 thalami, floor becomes hypothalamus, roof becomes epithalamus and part becomes subthalamus.

Mesencephalon changes into midbrain.

Rhombenecphalon subdivides into two subdivision; Metencephalon and Myelencephalon. From Metencephalon Pons and Cerebellum develop. Myelencephalon transforms into medulla oblongata. The distal part of the neural tube gives rise to spinal cord.

HEADACHE

Pain in head is called headache. Almost everybody experiences headache. One episode of mild headache may be due to exertion, stress or some causes which may not be alarming and you can afford to neglect.
Headache is a very common symptom. Almost everyone experiences headache at some stage of life. Despite of being so common it becomes sometimes it becomes a matter of concern.
So, one should not panic and should analyze the severity of the problem and proceed further for seeking the medical attention & investigations.
Lot of literature is available on the causes of headache but I would like to overly simplify this topic so that one can have an overview.


If headache is associated with exertion at the end of the working day and is over the vertex, frontal or occipital region of the skull and is relieved on taking rest or head massage, one should not worry.
if someone is very stressed and there is obvious stress then there can be psychogenic headache. That person should adopt the less stressful lifestyle and practice relaxation exercise , yoga  , and very rarely psychotherapy or some medicines may be required.


Maxillary or frontal sinusitis also causes headache.
Redness of eyes, frequent sneezing, cold , allergy may also cause headache.Cluster headache occurs in clusters.


In older persons headache may occur due to hypertension and temporal arteritis.



Refractive errors like myopia and hypermetropia may also cause periorbital pain and headache especially in young children going to school. So vision examination should also be done in patients complaining of headache.
If a child complains of headache it may due to refraction error in vision. Common cause is myopia when someone complains of difficulty in seeing distant things. child may not read the letters written on blackboard in a class and there may be decrease in scholastic performance in school. Another refractive error is hypermetropia which is difficulty in reading the small letters. Although, this is a common problem in people over 40 years of age, it is becoming more common in childrenm because of too much indulgence in mobile games, computer games and less outdoor play activities.
So common cause of Persistent headache is refractive error of vision.

Other common cause is sinusitis. Such patients will have frequent history of nasal infections, pain over the bony air sinuses in skull. Maxillary sinusitis, frontal air sinusitis may be diagnosed by tenderness and X-Ray Skull. Sometimes CT scan may be needed. Most of the patients are treated by antibiotics.

Common cause of headache is tension headache. In this type is headache pain is over the vertex, i.e, top of the head. Since the muscles are under continuous tension , such headache will diminish if head massage is given.

Hypertension, anemia may also cause headache.

Migraine is very common and typically paroxysm of throbbing type of headache on irregular intervals, unilateral, associated with vomiting. Migraine is more common in females. There are many variants of migraine.Migraine is the diagnosis of exclusion. Before labelling a ptient with this diagnosis all other causes must be ruled out, like anemia, brain tumor, hemorrhage, infection. CT scan or MRI of the brain rules out any intracranial mass occupying lesion.  It is normally hemicranial,i.e., involes one half of the head. It is usually throbbing headache and associated with nauses and vomiting. Migraine is recurrent and gradually the duration between episodes become less.


What should not be missed?
Any physician or person should not ignore headache due to brain tumor and subarachnoid hemorrhage due intracranial aneurysm rupture.
How to recognize headache due to brain tumor? Usually progressive, associated with vomiting, temporarily relieved after vomiting, may be associated with blurring of vision ( due to papilloedema), or other neurological deficit.
How to recognize headache due to subarachnoid hemorrhage caused by rupture of intracranial aneurysm? It is sudden onset severe headache ( bolt from blue, thunderclap headache which a patient in the age group of 4th - 5th decade, says that he or she had never experienced such type of headache in life time. Sometimes headache may not be so severe and it is called warning leak. There may be associated neck rigidity.
What is the most valuable investigation in the management of headache??
If  Visual examination of the patient is performed  and  Non contrast CT scan of the head is advised one will never be guilty of missing a life threatening brain condition like SAH ( subarachnoid hemorrhage and brain tumor) and it will guide the further course of treatment.

Sudden onset severe headache in a person of about 40 to 50 years of age which is so intense as patient describes that he or she had never experienced such headache in his or her life time,"Bolt from Blue," is typical of spontaneous subarachnoid hemorrhage ( SAH) due to rupture of intracranial aneurysm.

Head trauma, cervical spondylosis may also cause headache.

Headache associated with seizures is alarming. CT scan or MRI of the brain must be done.

Cranio-Vertebral Junction ( CV Junction)

Cranio-Vertebral Junction is the bony junction of the skull and vertebral column. It is formed by Clivus, Occipital bone and C1 and C2 vertebra.

This area is important as any abnormality in this area may lead to compression over the cervico- medullary junction, which is the junction of the cervical region of the spinal cord qnd medulla oblongata.

The abnormality at this region could be congeital anomaly or acquired.

This is simple diagram of the sagittal view shows location of CV Junction. TOO is abbreviation for transoral odontoidectomy . This surgery is done through oral cavity . Anterior arch of Atlas vertebra ( first cervical vertebra)  lies just anterior to the odontoid process of Axis vertebra ( 2nd cervical vertebra). Any dislocation of Atlanto-Axial Joint ( Atlanto axial dislocation -AAD) may compress over the medulla Oblongata, which lies just posterior to the Dens of the C2 vertebra.

Stability of the CV junction is mainly due to ligaments. 

The anterior atlanto-occipital membrane is the cranial extension of the anterior longitudinal ligament. It extends from anterior margin of foramen magnum to anterior arch of C1.

Posterior Atlanto-occipital membrane connects posterior margin of the foramen magnum to the posterior arch of Atlas.

Tectorial Membrane is the upward continuation of posterior longitudinal ligament. It connects the dorsal surface of the Dens of the Odontoid process of C2 vertebra anterior lip of the Foramen magnum.

Apical odontoid Ligament connects the tip of Dens to the anterior lip of Foramen Magnum.

Alar Ligament  connects side of the Dens to occipital condyles.

Transverse Ligament is the horizontal component of the Cruciate ligament which traps or straps or binds the Dens anteriorly against the C1. It is the strongest ligament.

Cerebral Angiography, Digital Substraction Angiography ( DSA)

Invention of Cerebral Angiography is an important historical landmark in evolution of Neuroradiology and Neurosurgery. 

In 1927, Dr Egas Moniz developed a technique of injecting a contrast material into the arteries . The dye or contrast used was Thorotrast. 

When a contrast or dye which is soluble in blood is injected into the common carotid artery the blood vessels become visible and look opaque on background of X-ray image of skull.  This technique of imaging the blood vessels of the brain is known as cerebral angiography. Rapid sequences of the X-ray images are obtained after injecting contrast into common carotid artery. Similar images could also be obtained when contrast is injected into the femoral artery.  Cerebral angiography allows visualization of blood vessels in and around the brain.

Before 1927, may be called  X-ray era, i.e., in the begining of 20th century, neurosurgery was possible by localization of the lesion by neurological examination and using the X-ray techniques. Application of X-rays in investigations like ventriculogram, encephalography, myelogram were used to localize lesions. 
Roentgen invented application of x-rays imaging in 1896.
Walter Dandy described pneumoencephalography and pneumoventriculography in 1918.
In 1921, myelography was introduced when jean Sicard a French clinician and his pupil Jacques Forestier injected analgesics into the spine of a patient suffering from low back pain and subsequently found that the oil they used as a carrier for the analgesic, lipiodol, was radio-opaque.
The invention of myelography encouraged the Portuguese neurologist Egas Moniz to develop ' Arterial Encephalography'.

After 1927, the dignostic ability of the physician changed dramatically. Using the technique of cerebral angiography, Norman Dott, in 1931,  demostrated cerebral aneurysm on cerebral angiography and later, Walter Dandy was able to operate a case of intracranial aneurysm, in 1933.

Cerebral angiography depicts the vessels along with X-ray of the skull. 

Later, with the use of computer, the background of skull image could be substracted. So, the artery or vein is visualized better. So, the technique of substracting the bony details  is called Digital Substraction  Angiography  ( DSA ). But, if somebody wants to see relation of the aneurysm against the bony landmark of the skull, it is still possible in DSA because the bone image was substracted digitally and computer again can depict the same.  Thus, DSA is gold standard investigation for detection and surgical planning for intracranial aneurysms.

                                                     Image of DSA , here the internal carotid artery is seen , the image is lateral view of the skull but the bony details have been digitally substracted so that one can focus on the ICA and its branches. ICA is seen as in neck, carotid siphon as a loop and intracranial branches. The first intracranial branch of ICA   which runs anteriorly is ophthalmic artery. Second intracranial branch which runs poseriorly is Posterior communicating artery. Anterior Choroidal artery is another intrcranial branch of ICA which is seen to traverse posteriorly on lateral view of DSA.

First investigation for investigating a suspected case of spontaneous subarachnoid hemorrhage is CT scan of the brain. Non-contrast CT scan reveals the site of the bleed, like blood in the anterior inter-hemispheiric space is suggestive of SAH due to rupture of anterior communicating artery. Then, the second investiation is to know the detail of the aneurysm, which is done by DSA.

Since, DSA is an invasive procedure, so the another option is to go for CT angioprphy. MR angiography ( MRA) is a noninvasive procedure and it does not require any injection. But MRA is less sensitive than CT angiography and DSA.

Digital Substraction Angiography ( DSA) involves passing a catheter in the femoral artery over the anterior aspect of the thigh in the femoral triangle and then advancing the catheter upward. Then, injection of a contrast material ( Dye) through a catheter. Once catheter is at the arch of aorta it needs to be negotiated to the carotid artery and vertebral artery. So, anatomy of arch of aorta is important.

                                         The contrast is injected into the Femoral artery on right side and then catheter is advanced upward into the arota under the fluroscopic guidance. At the arch of aorta the catheter is negotiated into the artery depending upon the need of DSA. On the right side there is first branch of arch of aorta, brachiocephalic trunk. Right common carotid artery is a branch of brachiocephalic trunk.
Left common carotid artery is a direct branch of arch of aorta. Left subclavian artery is also a direct branch of arch of aorta and vertebral artery is a second branh of subclavian artery.

Spontaneous subarachnoid hemorrhage due to ruture of intracranial aneurysm commonly occurs in the age group of 40-60 years with a peak incidence in the fifties.
Aneurysm bleed is the commonest cause of spontaneous SAH ( about 85%). 
Other common causes of spontaneous SAH are:  artriovenous malformations ( AVM), hemorrhage from tumor, pituitary apoplexy, vasculopathy ( like collagen vascular disease, amyloid angiopathy , arterial dissection) , haematological ( anticoagulant therapy, leukaemia, hepatic or renal disease induced coagulopathy ) and drugs like cocaine, amphetamine and ephedrine.

Subarachnoid hemorrhage (SAH) is a neurological emergency  characterized by hemorrhage into the subarachnoid space, and may present as sudden, severe headache ( as bolt from blue ) which patient may state that he or she may have never experienced before. Sentinel hemorrhage occurs in about 40% of patients with SAH. This is also known as " warning leak". Nuchal rigidity or meningismus is noted in 50% of patients due to meningeal irritation following SAH. Hemiparesis, focal neurological deficits including cranial nerve deficits are other common features. Fundus examination may reveal papilloedema and subhyaloid hemorrhage.

On the basis of GCS and Focal deficit, the severity of the clinical presentation of the patients may be graded into 5 grades , according to the World Federation of Neurological Surgeons  (WFNS).
In WFNS Grade 1 the patients are of GCS 15/15 and have no focal deficit. And, if patient's GCS is 13 or 14 then it is Grade 2. And patient has a focal deficit with a GCS of 13 or 14, his grade becomes Grade 3.   poor GCS of 7-12 makes a patient of grade 4 and if patients GCS is 6 or less then his garde becomes 5, irrespective of the presence or absence of focal deficit.

NCCT ( NECT) , i.e., Noncontrast or nonenhanced CT scan of the barin is the first investigation of choice. It shows hyperdensity in the subarachnoid space and may indicate the site of bleed. or example, anterior communicationg artery aneurysm bleed shows blood or hyperdensity in the anterior interhemispheric cisterm. the ruture of the Middle cerebral artery may present with hematoma in the temporal lobe or in the sylvian fissure of that side.

Fischer's grading of SAH on the basis of CT findings:
In Grade 1: there is no detectable blood on CT scan
Grade 2 : Diffuse thin  SAH  less than 1 mm thickness, & if thickness of clot is more than 1mm then it is labeled as Grade 3.
Grade 4: Intraventricular or intracerebral clot with diffuse or no subarachnoid hemorrhage

If  CT scan is normal and still there is strong suspicion of SAH, then the next  investigation is Lumbar Puncture, which reveals xanthochromia. 

Common locations of intracranial aneurysms include Anterior communicating artery ( 30%), the junction of the ICA and Pcom ( 25% ), MCA bifurcation ( 20% ), ICA bifurcation ( 7.5%). Around 7% arise from the basilar bifurcation and 3% arise from the PICA, a branch of vertebral artery.

Digital Substraction Angiography ( DSA) or CT Angiography ( CTA) is the investigation of choice. MR angiography ( MRA) does not use any contrast and it is a good non invasive screening investigation.

Source: Wikipedia