396The four categories of cerebral impairment are:

396     The four categories of cerebral impairment are:

a)      disturbances of levels of consciousness or awareness:

i)        Table 12.1.1: Permanent disturbances of levels of consciousness and awareness;

ii)      Table 12.1.2: Epilepsy, seizures and convulsive disorders;

iii)     Table 12.1.3: Sleep and arousal disorders;

b)      impairment of memory, learning, abstract reasoning and problem solving ability:

i)        Table 12.2: Impairment of memory, learning, abstract reasoning and problem solving ability;

c)       communication impairments:

i)        Table 12.3: Criteria for rating impairment due to aphasia or dysphasia; and

d)      emotional or behavioural impairments:

i)        Table 12.4: Emotional or behavioural impairments.

397     WPI ratings from these four categories of cerebral impairment may not be combined with each other. The highest WPI rating from these four categories is to be used. Unless otherwise indicated, the highest WPI rating may then be combined with:

a)      a WPI rating from any other table or tables in Chapter 12 – The neurological system other than tables covering the first four categories; and

b)      WPI ratings from tables in other chapters.