Image Based Question-66199

Correct Answer » B Explanation

Ans:B. Macrocephaly

Macrocephaly

• It is defined as head circumference more than two standard deviations (SD) above the mean value for a given age and gender.

• It has to be differentiated from megalencephaly, which is defined as increase in the size of the brain parenchyma.

Etiology

Enlargement of skull bones

• Hyperostosis cranii – associated with disorders such as osteogenesis imperfecta, achondroplasia, and osteopetrosis

• Secondary enlargement due to bone marrow expansion – as seen in thalassemia major
  Increase in volume of cerebrospinal fluid

Hydrocephalus

• Choroid plexus papilloma
• Benign familial macrocephaly(most common cause)

Megalencephaly

• Leukodystrophies – Canavan disease, Alexander disease, megalencephalic

• leukoencephalopathy with subcortical cysts

• Lysosomal storage disorders

• Neurocutaneous disroders – Tuberous sclerosis, Sturge-weber syndrome, neurofibromatosis, Gorlin syndrome

• Autism spectrum disorder

• Other syndromes – Fragile X syndrome, Cowden syndrome, Sotos syndrome

Increased intracranial pressure (ICP)

• CNS infections
• Pseudotumor cerebri

Mass lesions and increase in volume of blood

• Tumor
• Intraventricular hemorrhage, subdural hematoma, arteriovenous malformation.

Dolichocephaly is a condition where the head is longer than would be expected,relative to its width.

Brachycephaly is the shape of a skull shorter than typical for its species.

Plagiocephaly, also known as flat head syndrome,is a condition characterized by an asymmetrical distortion (flattening of one side) of the skull.

Scaphocephaly describes a specific shape of a long narrow head that resembles an inverted boat