Tuesday, March 23, 2010

Epiconus, Conus and Cauda Equina syndromes


Epiconus Syndrome:

The epiconus syndrome presents with the following clinical features.

A sensory disturbance in the leg (transverse, saddle, radicular, or socks type).

Motor deficit as a sign of lower motor neuron involvement (foot drop, fasciculation, muscle atrophy).

Diminished deep tendon reflexes.

Occasional coexistence of positive pathological reflexes (Babinski's and Chaddock's signs).

Diminished vibration sensation, and

Bladder and bowel dysfunction.

Conus Medullaris Syndrome:

Mixed LMN and UMN type of picture seen

During the Acute phase paralysis of lower extremities with flaccid rectal tone and urinary retention are found.

In chronic phase there is evidence of atrophy and hyperreflexia.

The defecits tend to be symmetrical.

The prognosis for bowel and bladder function is relatively poor.

In pure Conus medullaris syndrome as in Intramedullary lesions there is total absence of motor disturbances inlower limbs and absent Babinski and other pathological pyramidal tract signs

CaudaEquina Syndrome:

Early radicular type of pain, Late sphincter disturbances,  and Asymmetrical sensory findings are characteristics.

Pain is unilateral or asymmetrical 

Develops flaccid, Hypotonic, areflexic paralysis true peripheral type of paraplegia.

Asymmetric sensory loss in saddle region involving anal, perineal and genital regions.

Ankle jerk is absent and has variable Knee jerk


Epiconus, Conus, Periconus and Cauda Equina

Anatomically, the epiconus comprises the cord segment between L4 and S1, corresponding to the T12 and L1 vertebrae.*

The conus medullaris consists of the cord segment between S2 and S5 as well as coccygeal segments.**

Anatomically periconus includes the Epiconus and Conus Medullaris

The cauda equina is a structure within the lower end of the spinal column that consists of nerve roots and rootlets from spinal segments L3 to Coccygeal nerve. At the base of the Cauda Equina, there are approximately 10 root pairs, 3-5 lumbar, 5 sacral, and the single coccygeal nerve.

*= Bullough P G, Boachie-Adjei O. Development of the Spinal Cord. 

 In: Atlas of the Spinal Diseases. JB Lippincott: Philadelphia, 1988,pp53.

** =  Di Pietro M A. The conusmedullaris : normal US findings throughout childhood.

Radiology 1993; 188: 149 - 153.

Monday, March 22, 2010

Multifocal Gliomas

Multi focal gliomas are categorised

1. Spatially as connected or disconnected

2. Temporally as Synchronous ( if present with initial presentation and Metachronous ( if develop during the follow up)

Multifocal glimas are called

1. Multiple - If they are present at the same time but are separated spatially 

2. Multicentric - If they are separated both spatially and temporally


Sunday, March 21, 2010

Kindling

Kindling = easily combustible material for starting a fire (Webster's Dictionary) .

In Neurology

Def: The tendency of some regions of the brain to react to repeated low-level electrical stimulation by progressively boosting electrical discharges, thereby lowering seizure thresholds.

The phenomenon of kindling in epilepsy was first discovered accidentally by Graham Goddard in 1967 when studying the learning process in rats which included electrical stimulation of the rats' brains at a very low intensity, too low to cause any type of convulsion.

Goddard and others later demonstrated that it was possible to induce kindling chemically as well (Hargreaves, 1996.)

Kindling is a widely used model for the development of seizures and epilepsy in which the duration and behavioral involvement of induced seizures increases after seizures are induced repeatedly.

It is used by scientists to study the effects of repeated seizures on the brain.

In the kindling model, seizures begin to occur spontaneously after repeated subconvulsive stimul.

The seizure that occurs after the first electrical stimulation lasts a short time and is accompanied by a small amount of behavioral effects compared with seizures that result from repeated stimulations.

The lengthening of duration and intensification of behavioral accompaniment eventually reaches a plateau after repeated stimulation.


Friday, March 19, 2010

Criteria for Neurofibramatosis II

NF II Due to mutation of chromosome 22

Presence of one of the following

1. Bilateral eigth nerve masses seen with appropriate imaging technique

2. A parent, sibling or child with NF II and either a unilateral mass of either CN mass or any two of the following

Neurofibroma

Meningioma

Glioma

Schwannoma

Juvenile posterior subcapsular lenticular atrophy

Diagnostic criteria for Neurofibramatosis I

NF I ( Mutation of chromosome 17)

Presence of 2 or more of the following

1. Six or more Cafe-au-Lait Spots of

           >5mm in pre pubertal age group 

           >15 mm in post pubertal age group

2. Two or more neurofibromas of any type or 1 plexiform neurofibroma

3. Freckling in axillary or Inguinal regions

4. Optic gliomas

5. Two or more Lisch nodules ( Slit lamp examination)

6. A distinctive ossesous lesion like Sphenoid dysplasia, Thinning of long bone cortex with or without pseudoarthrosis

7. A parent or sibling or child with NFI according to above criteria

Neurocutaneous markers

Various Neurocutaneous markers that can be seen are

1. Cafe-au-lait spots

2. Lisch Nodules ( Slit lamp Examination)

3. Axillary and inguinal freckling

4. Cutaneous Neurofibramatosis

5. Facial Angiofibromas

6. Multiple Ungual Fibromas

7. Shagreen Patch

8. Adenoma Sebaceum

9. Hyper / Hypo melanotic macules

10. "Confetti" Skin Lesions ( Brightly colored lesions)

11. Randomly distributed enamil pits in deciduous or permanent teeth

12. Gingival fibromas

13. Ash - Leaf Spots

14. Facial angioma or portwine stain 

15. Hemangiomas over the spine

16. Dermal sinus

17. Hairy tuft over sacrum

18. Sacral dimples and pits

Monday, March 1, 2010

Brachial Plexus Anatomy 2

Branches from the Roots (3 Branches)

1. Nerve to Serratus anterior - ( Long Thorasic nerve) - C5,6,7

2. Nerve to Subclavius - C5,C6

3. Dorsal scapular nerve - C4,C5

Branches from Trunks (1 Branch)

1. Suprascapular Nerve ( C5-C6) Supply Supraspinatus and Infraspinatus

There are no branches from Divisions

Branches from Cords

Medial cord ( 5 branches) - M4U

1. Medial pectoral nerve

2. Medial root of Median Nerve

3. Medial cutaneius nerve of arm

4. Medial Cutaneous nerve of fore arm

Lateral cord ( 3 branches) LML

1. Lateral root of Median Nerve

2. Musculocutaneous Nerve

2. Lateral pectoral Nerve

Posterior Cord (5 Branches) - ULNAR

1. Upper subscapular

2.Lower subscapular

3. Nerve to Lattismus dorsi ( Toracodorsal Nerve)

4. Axillary Nerve

5. Radial Neve



Brachial Plexus Anatomy


Formed from C5 to T1 Roots

Roots unite to form Trunks Upper , Middle and Lower trunks ( From the anterior border of Scalene anterior)

Three trunks divide into 3 anterior and 3 posterior divisions ( From the lateral border of 1st Rib)

anterior divisions of the upper, middle, and lower trunks
posterior divisions of the upper, middle, and lower trunks

In relation with the 1st part of Axillary artery form 3 Cords The Medial, Lateral and Posterior Cords

Branches emerge from the Cords