Upper Pons Cross‑Section: Trigeminal Nuclei and Lemnisci Unpacked

Upper Pons Cross‑Section: Trigeminal Nuclei and Lemnisci Unpacked

Question 1. Enumerate the main structures seen in the transverse section through the upper part of the pons.
Answer: The main structures seen in the transverse section through the upper part of the pons are as follows:

Pontocerebellar Angle Syndrome Explained: From CN VIII Schwannoma to Clinical Signs

• The chief (main) sensory nucleus of the trigeminal nerve
• Motor nucleus of the trigeminal nerve
• The mesencephalic root of the trigeminal nerve
• Trigeminal lemniscus
• Lateral lemniscus

Question 2. Write a short note on the pontocerebellar angle syndrome.

Answer.  Causes Of Pontocerebellar Angle Syndrome

Involvement of the lateral region of the caudal part of the pons near the pontocerebellar angle by Schwannoma of CN 8.

cross section of pons anatomy

Clinical Features of Pontocerebellar Angle Syndrome

• Ipsilateral deafness due to involvement of the cochlear nerve.
• Ipsilateral imbalance and asynergia due to involvement of the vestibular nerve.
• Ipsilateral lower motor neuron type of facial palsy due to involvement of the facial nerve.
• Ipsilateral loss of pain and temperature on the face due to the involvement of the spinal nucleus and tract of CN 5.