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The rule of 4.

2 user entries

dr. no
user_forums Rule of 4 in the brainstem Feb 01, 2009 @ 08:44

Hello Everyone. I just found this very interesting and would like to share it.

 The are:

4 structures in the midline beginning with M.

4 structures to the side beginning with S.

4 cranial nerve in the medulla, 4 in the pons, 4 above the pons (2 in the midbrain)

the 4 CN nuclei that are in the midline are those that divide equally into 12 except for 1 and 2, that is 3, 4, 6, and 12 (55, 7, 9 and 11 are in the lateral brainstem) 

 Medial nuclei

1 MN motor nucleus (CN 3, 4, 6, and 12)

2. MLF medial longitudinal fasciculus

3.ML medial lemniscus

4. Motor pathway

Lateral nuclei

1. SC,Spinocerebellar

2. ST, Spinothalamic

3. SYM. Sympathetic

4. SV. Sensory nucleus of the 5th.

 Ipsilateral or contralateral (lesions above the medulla):

Motor (contralateral limbs)

Sensory (Contralateral limbs)

Ataxia (ipsilateral except in midbrain)

Cranial nerves: ipislateral with exceptions.

This is simplified and not always true.


Author: Gates, P.<a href=""><font color="#336699">1</font></a>

Source: <a href=";jsessionid=3dv50aadbgpmi.alexandra" title="Internal Medicine Journal"><font color="#336699">Internal Medicine Journal</font></a>, Volume 35, Number 4, April 2005 , pp. 263-266



user_forums Re: Rule of 4 in the brainstem Feb 01, 2009 @ 19:21
Welcome. And thanks for the helpful heuristics.

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