=Monoplegia= is a circumscribed paralysis, as of one limb, or on one side of the face, one group of muscles or a single muscle. It may be due to cerebral, spinal or nervous lesion. _Cerebral monoplegias_ are distinguished by: 1st, initial spasm; 2nd, absence of anæsthesia; 3d, persistence of nutrition; 4th, paralysis greatest in the distal portion of the member. =Localized Paralysis= is usually due to lesion of a nerve, and is both motor and sensory. If due to a spinal lesion it usually affects one or more groups of muscles. In case the lesion is in the nerve, be guided, in investigating it, by Van der Kolk’s law, that the sensory fibres are usually distributed in the skin corresponding to the muscles which receive the motor fibres. =Pseudo-paralysis= occurs from muscular disease, injury, inflammation or degeneration and has no appreciable central nor nervous lesion nor anæsthesia. =Spasm= (_Hyperkinesis_); abnormal violent muscular contractions with or without loss of consciousness. =Tonic= (_tetanic_) =Spasm= is violent and continuous. =Clonic Spasm= is rapidly intermittent:—Contractions and relaxations. =Tremor= (_trembling_) consists in small, intermittent, involuntary contractions. =Hemispasm= affects the face, or limbs, or both, on one side of the body and may precede hemiplegia. =Monospasm= affects one limb, one group of muscles or a single muscle. It may be due to lesion of the brain, of the spinal cord or of the nerves. Thus it may imply commencing disease of the motor centres or tracts. =Spasms of the Eyeballs= (rolling of globe to one side), and =Spasms of the Eyeballs and Head=, are important indications of apoplexy. They imply disorder (commencing irritation) of the cerebral motor areas. Advanced disease would probably determine hebetude, coma, drowsiness, or palsy. If epileptiform it turns away from the lesion. If hemiplegic it turns toward the lesion and away from the paralysis. If lesion of the pons it turns away from the lesion. =Paraplegic Spasm= is a tonic spasm, partial in degree, causing stiff, tetanoid (spastic) walk. In all four extremities there may be mixed paresis and contraction. This often attends on hemorrhage into the meninges. =General Spasms=, convulsions as in Eclampsia, Epilepsy, Chorea, Tetanus. =Local Spasms= may be rhythmic or not, in slight cases to be seen only in the eyelids or superficial muscles as twitching, and occur in neurasthenia, or in poisoning by strychnia, brucia and other motor nerve poisons.