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Anatomical peculiarities of 3,4,6th cranial nerve

The 3rd cranial nerve-oculomotornerve
The oculomotor nuclear complex is located in the the middbrain at the level of superior colliculus. This has one unpaired and four paired nuclear columns.
The unpaired column constitute
  • Edinger-Westphal nucleus
  • Subnucleus for levator palpebrae superioris. 
The paired nuclei constitutes
  • Subnuclei for superior, inferior and medial recti and inferior oblique.
4th cranial nerve-Trochlear nerve
  • Trochlear nerve passes posteriorly and the fibres from the right and left trochlear nuclei decussate on the dorsum of mid brain. 
  • This is the only cranial nerve that emerges dorsally from the brainstem. 
  • The left trochlear nucleus sends fibres to the right superior oblique muscle and vice versa.

6th cranial nerve-Abducent nerve 
  • Abducent nerve has a very long intracranial course and supplies the lateral rectus muscle..
  • Because of its long intracranial course, this  nerve  is affected in conditions producing raised intracranial tension, hence producing a false localizing sign.

Ocular myoclonus clinical significance

Rapid involuntary conjugate saccadic movement of eyes
It is described as rapid, involuntary, multivectorial (horizontal and vertical), unpredictable, conjugate fast eye movements without intersaccadic [quick rotation of the eyes] intervals)
Ocular myoclonus associations
  • Opsoclonus Myoclonus Syndrome (OMS) is also called as Opsoclonus-Myoclonus-Ataxia (OMA), is a rare neurological disorder  which appears to be the result of an autoimmune process involving the nervous system
  • Seen in Postencephalitic syndrome 
  • Neuroblastoma
  • It may be seen associated with  viral infection ,perhaps St. Louis encephalitis, Epstein-Barr, Coxsackie B, enterovirus, or just a flu
  • OPM-palatal myoclonus when associated with abnormal eye movements,it is called "oculopalatal myoclonus", or OPM.   A clicking sound is commonly heard in this symptom

Ocular dipping

Ocular dipping is an abnormal eye movement consists of cycles of eye movements occurring spontaneously, that are characterized by a slow conjugated downward deviation followed after a delay by a quick return to mid position. 

Periodic slow downward movements followed by fast Upward movement  to the primary position
Slow down-fast up
It is also called as inverse ocular bobbing
Causes of ocular dipping
  • Ocular dipping is only described in unconscious patients, especially those in anoxic coma
  • Diffuse or multifocal encephalopathies 
  • Diffuse structural brainstem damage.
  • Creutzfeldt-Jakob disease.
Spontaneous eye movements are useful clinical signs in coma, although they rarely have localizing value. The best-known exception to this rule is ocular bobbing,that is found in pontine lesions.

What is Dyspepsia?

Dyspepsia is a term to denote a variety of alimentary symptoms arising form upper gastrointestinal tract.
Symptoms  includes 
  • Upper abdominal pain ± related to food
  • Heart burn, regurgitation, water brash
  • Anorexia, nausea, vomiting
  • Early repletion and satiety after meals
  • Flatulence, belching and bloating.
Causes of dyspepsia
Organic dyspepsia
Functional dyspepsia
Organic causes of dyspepsia
  • Peptic oesophagitis
  • Peptic ulcer
  • Upper GI malignancy
  • Hepatobiliary disease
  • C/c pancreatitis
  • Other system disorders - CRF, CHF etc.
  • Drugs - NSAID, corticosteroids
  • Alcoholism, pregnancy
Functional dyspepsia [nonulcer dyspepsiaI
It is due to motor dysfunction of upper gastrointestinal tract mediated by neurohumoral mechanism
What are the Alarm features in Dyspepsia
  • Weight loss
  • Anemia
  • Vomiting
  • Hematemesis
  • Melaena
  • Dysphagia
  • Palpable abdominal mass.


Importance of past history in GIT

Past history is very important in gastrointestinal system

  • History of Jaundice indicate viral hepatitis
  • Drug intake - history of drug intake such as rifampicin. INH. anabolic steroids pills are risk factors for jaundice .NSAID intake for melena  or history of any herbal remedies
  • Blood transfusion or transfusion of any blood products (viral hepatitis C. D and G).
  • Recent tattooing or acupuncture: Drug abuse.to rule out viral hepatitis
  • Alcohol consumption predispose to cirrhosis
  • Tuberculosis can cause ascites due to tuberculous peritonitis.
  • Haematemesis or melena (peptic ulcer, ruptured oesophageal varices, gastric malignancy)-
  • Fever seen in tuberculosis, hepatocellular failure
  • Haematochczia occur due to lower G. 1. malignancy. haemorrhoid

Points to note in a renal lump :

Once the kidney is palpable examine for the folllowing
  • Site
  • Size.
  • Shape (ovoid normally).
  • Consistency (resilient or firm in feel).
  • Margins (rounded).
  • Surface (normally smooth surface: irregular in polycystic kidney).
  • Tenderness.
  • Movement with respiration (normally kidney shows slight movement with respiration).
  • Whether bimanually palpable and ballottable.
Renal angle tenderness
In case of left sided renal lump—Examine for band of colonic resonance over the lump (by
Remember, a kidney lump is bimanually palpable and ballottable. The kidney is ballottable
Because it is a posterior abdominal organ.

How to elicit Tenderness over the renal angle?

Patient is asked to sit and the angle formed by the 12th rib and lateral border of erector spinae muscle is pressed by the ball of the thumb—"Murphys kidney punch". This  test is done on both sides.
Renal  angle is tender in the following conditions
  • Acute pyelonephritis
  • Perinephric abscess
  • Nephrolithiasis, 
  • Tuberculosis of kidney